Convoy Disruption: 1941, 1942.2 & G40 Submarine economic warfare

[CWO Marc]

A short idea on its own:

If we treat convoys as quasi-units in the way we’re discussing, they would of course remain open to attack by enemy units (as in the OOB rules, so that part isn’t new), but a new HR element that opens up is the concept of the player who owns a particular convoy might be able to “attach” (with an “h”, not a “k”) some of his naval units to a convoy specifically for purposes of convoy defense.  The player could likewise detach naval units from convoys, if desired, as the reverse operation.  The general idea (I haven’t worked out any specifics) is that such an attachment operation would create a trade-off: a naval unit attached to a convoy for convoy-defense purposes would lose the ability to perform the other (non-convoy) things that a naval unit can normally do in a sea zone, but the convoy would gain some sort of enhanced defensive bonus, over and above the “normal” protection it would gain under the OOB rules from the presence of “normal” (unattached) ships in its sea zone (for instance the normal anti-sub abilities of a normal destroyer).

[General 6 Stars]

I’d use these.

[CWO Marc]

@SS:

I’d use these.
Convoy Markers.png (39.71 KB, 150x127 - viewed 4 times.)

Very nice.  I like them.

Also on the subject of tools for this house rule: For each game for which it’s used (Global, 1942, etc.), we’d need to make a reference chart.  I’ve posted below a rough draft of what a couple of lines from such a chart might look like, with purely invented entries on each line.

[CWO Marc]

An additional idea (especially if we have multiple convoys with different and/or changing values): using the income tracking charts to keep track of both types of IPCs, using two types of markers: one type for regular income and one type for convoy bonuses, as shown below (purely as a made-up example).

[baron Münchhausen]

I pretty like where it is going.
The various SZ pointed out as good candidate for Convoy.
I just not have time to discuss some ways of doing Convoy Raiding and interactions with regular combat and units sharing the SZ.
Later,
Keep up the good work.

[Black_Elk]

Great feedback Marc! I’m sensing some pretty broad agreement here in the ways this National Convoy system might work.

I think a 3 ipc convoy (3 gray chips) is best. Since it would work on all A&A gameboards.

Keep the value consistent for all nations. Convoys always = 3, so its easier to understand and easy to track. Tie the raids to the number of warships passing either 1, 2, or up to 3 (cap’ing the max damage at 3).

I favor making the damage automatic 1:1 on IPCs raided. Or ships:chips.
Mainly so we dont have to slow down the conduct combat phase with any more rolls.

Or if you do want to preserve the roll, instead of having a roll for attacker damage, just make the roll for defense. I’m not sure about this idea, but can imagine some ways it might look.

This could be like the older rules for AAGuns, back when AA guns were “always active.” Any flyover had to face a shot, you could do the same here at sea. We might say an “active convoy” (one with defending warships) can fire a shot against any units that are attempting to raid into it.

Or how about this for an idea… A full convoy (3 chips) gets a single shot rolled at 1, against enemy raiding vessels. Just like an AAgun, for the water. This could be a single shot vs all ships, or against only 1 ship, or you could cap it at a Max of 3 shots/3 ships. So the mechanic is familiar.
Or alternatively, you could allow the purchase of “Convoy Defense”, as a new 5 ipcs unit (represented by the AAgun) and placed on top of the Convoy Roundel/Chips. Or you could allow ships in the SZ to move on top of the Roundel, at which point it is considered “Convoy defense”, and the naval unit behaves similar to the way Aircraft do on Intercept. Not entirely sure which system is optimal, but it certainly seems possible to set something up along those lines. I like the idea of “the roll” just being for the “raider’s” defense (whether or not their ship is destroyed during the raid), rather than having the raider make a roll to determine the amount of damage vs the convoy. Though I suppose you could have both if you really wanted.

Probably any of those, or something similar could be made to work, but I’d try to keep everything as simple as we can, just for ease of adoption.

I also like the special convoy markers SS shared, and the idea to create a set up/chart card for the most popular games or rulesets. Such a system could probably work on any Axis and Allies gameboard, and might be a cool way to support the idea of a “Naval expansion” to the game. Because the influx of cash from the Convoys is located “at sea” it really does facilitate an increased likelihood that players use the extra money on ships.

@CWO:

I would suggest giving the flag roundel itself no IPC value, and thus having the IPC value of a convoy (0 or 1 or 2 or 3, depending on whether casualties were sustained) expressed exclusively by the chips under the roundel.

Agreed, I prefer this method. Basically the roundel serves only to indicate the location/existence of a Convoy, not its IPC value. The IPC value is indicated by the number of chips. This way, once the National Convoy Roundel is placed in a SZ during the initial board set up, it never has to be removed.

The only possible exception to this is in Global/Pacific 1940, the convoys around the Dutch islands, since the Dutch are not a player Nation, and thus have no roundels. I could launch into another diatribe about why I find special exclusive one-off rules so annoying in A&A, but I’ll resist the urge. Suffice it to say we have 2 options here with the Dutch in G40.

Option 1. Ignore the OOB “Dutch Island” Convoys markers completely. (i.e we don’t place Convoy Roundels in those sea zones.) This has the advantage of being simpler, and would prevent Japan from collecting too much convoy money outright. The downside is that there is a bit less variety to the overall convoy campaign in the Pacific. If we choose to ignore the Dutch Convoys, I would use the logic that “this particular convoy traffic from the occupied dutch islands” is being represented by other convoys in some Adjacent zone. There are plenty of these to work with already, on both sides. For example, the Japanese convoys in sz 36 (Hainan), and sz 20 (Formosa) could be envisioned as encompassing the shipping lanes for the entire adjacent region, including the Rich Islands, Indo-China etc. If you wanted to create some Convoy near sz 34 (Palau) or sz 34 (Caroline Islands), in order to offset the Dutch convoys we ignore, that is doable as well under the new system, and this avoids the problem of changing dutch ownership as it relates to convoy ownership. Prior to the DoW, or from an Allied perspective, the convoy Dutch convoy traffic can be covered, by other Allied convoys in adjacent zones, such as sz 37 (Malaya/Singapore) , sz 43 (Borneo/Sarawak), or sz (35 Philippines.)

Option 2. Allow any Nation to take control of the Dutch Convoys. This has the advantage of a bit more novelty for the Allies or Japan. Here the logic would be, ‘well, the Dutch rules are unique OOB, and this rule just follows suit.’

There is a definite downside that option 2 violates the new concept we’re trying to introduce that National Convoys are “National,” and don’t change ownership depending on who controls some surrounding territory, except in this one weird instance. There is also the potential the the Dutch convoys become too potent of a target for Japan, distorting their already out-sized importance (as Allied targets.) So I think it might be easier to just ignore all those convoys, remove them from play, and focus on the potential locations immediately adjacent instead. This also contains within it the idea that the Dutch Island Convoy resources are “bound” elsewhere, and so we don’t really need to have a convoy for each Dutch island. The Island itself is enough of a draw already, instead we could put the convoy emphasis one space out just to simplify.

[Black_Elk]

@CWO:

In purely military terms, one helpful concept to keep in mind is the definition of a raid: a limited-objective and temporary strike into enemy-controlled territory.  Raiding forces enter an enemy-controlled territory, attack one or more specific targets, then return home.  Their purpose isn’t to take and hold ground; that’s the job of an army offensive (on land) or of an amphibious landing (on islands and coasts).  WWII strategic bomber attacks (in the real world) were examples of raids, and so were the German U-boat campaign against the Allied convoys in the Atlantic and the American submarine campaigns against Japanese convoys in the western Pacific.  Surface warships, by contrast, are not inherently raiding forces: they sometimes do conduct raider-type operations into enemy-held waters (the Bismark sortie was one such operation), but they sometimes function in other ways too: for example taking and holding territory (example: the Americans at Leyte Gulf) or serving as launching platforms (from areas of the sea  which they do control) for air attacks into areas of the sea which they don’t control.

That’s an interesting point. I know that the term “Raid” itself in English, is etymologically related to our word “Ride” and comes to us from early ideas about mounted combat. The speed and the shock! I picture some Indo-European horse-riding warlord, descending on the hapless enemy, trampling, looting and burning, before galloping off to the next spot post haste.
:-D

Maybe subs or other raiding vessels could just work like that? They pass through the convoy, knock off a single chip on their way, and just keep it simple.

My main concern with a “defensive convoy shot” against raiding units, (a shot that could actually destroy the enemy’s ships), is that this will make the trade of 3 IPCs vs potential TUV destroyed too risky for the attacker.

Perhaps the roll, if there is to be a roll, should just determine whether the convoy Chip gets knocked off, or not. In other words, raiding does not put the raiding vessel at risk, but the Convoy defender still has a chance to “evade.” No convoy damage, the chip stays in place. The baseline for this could be 1d6, if the defender rolls a 1, no damage occurs. Otherwise 1 chip is removed.

Under that system, you could perhaps create some way that a defender can put one of their ships in a sz “on convoy defense” during a raid. The ship moves on top of the roundel, and this changes the roll somehow? Perhaps instead of rolling a 1 to “evade”, it evades at 3, or 50/50. Something along those lines.

[CWO Marc]

@Black_Elk:

I’m sensing some pretty broad agreement here in the ways this National Convoy system might work.

Yes, things seem to be coming along nicely indeed.

I’m posting below (assuming “.doc format” Word documents are postable here, which I think they are) a document I was working on this evening prior to reading your posts from today.  It’s a document that could be useful to you and Baron and anyone else who wants to contribute to this HR development process.  Basically, it’s a blank chart (meant to be expandable) for preparing lists of potential convoy locations, IPC values and operating conditions.

The charts where the final choices (for the various A&A games) will eventually be written down once we’ve worked out the complete HR will probably look similar – but for the moment this is just a working document to record ideas and proposals for discussion as we decide where to put these convoys.  I kept it as generic as possible, for example by allowing (potentially) for different convoy values, even though – as discussed above – there are advantages to giving them all a standard value of 3.  I also included nations that may or may not actually get convoys (including the Dutch, who you mention in one of your posts).  I don’t know to what extent this document might or might not be useful, but the folks here are welcome to play around with it if they wish.

Blank Convoy Chart Global 1940.doc

[baron Münchhausen]

About the Raiding mechanism, do you think this can be too complicated?

Any 1 Submarine raiding a Convoy Zone: auto destroy of all 3 IPCs.
The Merchant’s convoyed ships didn’t see them coming.

Any 1 surface warship (and up to 2 planes paired with Carrier) needs to make an attack roll against Merchant’s Convoy. Any hit makes for the destruction of 3 IPCs.

When there is warships defending the Convoy SZ,
attacking surface warship makes regular combat BUT the 3 IPCs Convoy is safe.
So any one can use a DD blocker to protect the Convoy SZ.

When Submarines are part of the battle, the attacker can choose to assign a Submarine’s hit to the Convoy, instead of an enemy warship chosen by the owner’s (as OOB combat rule for casualty).

This simply means that with Subs, the attacker can destroy enemy units AND the 3 IPCs Convoy.

In this case, the Convoy is played as an additional free hit (like these puts on Carrier or Battleship) without loosing a combat unit.

[CWO Marc]

Here’s a summary of where things appear to be at the moment with the convoy house rule proposal.  This summary is meant to be revised on an ongoing basis as points needing decisions [shown in square brackets] are discussed and finalized.

• The HR convoy system is designed for potential use with any global-scale A&A game, or with Europe 1940 and Pacific 1940 if these games are played on their own.  Separate convoy setup charts for the system will be required for each of these games because they have different IPC structures and different SZ numbering systems.  [For a working draft of what these charts might look like, see CWO Marc’s post of April 17, 2015.]  In the case of Global 1940 (and its two constituent games), the HR is meant to replace the existing OOB convoy zone system.  In the case of the 1942.2, 1941 and (potentially) 1914 games, the HR is meant to introduce a convoy system where none exists in the OOB rules.

• Possible name suggested by Black Elk for the system: National Convoy House Rule.  Rationale: this distinguishes the HR from the “local convoys” in Global 1940.  [Question : Might the National Convoy / Local Convoy terminology create the impression that Global 1940 has two convoy systems, rather than a HR system that replaces the OOB system?]

• The convoys in the HR system provide extra IPC income, over and above the normal IPC income which the various powers collect.  These two types of income are tracked separately.  This tracking can be done with separate IPC charts, or by using two different types of markers on a single chart.  (For an illustration of the latter idea, see CWO Marc’s final post of April 16, 2015.)  The bonus income generated by each power’s convoys is added (at the Collect Income phase of the game) to the overall income of each power (in contrast with the Global 1940 OOB convoy system, which affects the IPC value of specific land territories.)

• Convoys occupy fixed positions on the game map.  Each SZ can contain either one convoy or no convoys.  The nationality and the position of convoys is marked on the game map according to the convoy setup charts [which still need to be developed] for that particular A&A game.  Convoys can be marked using either A&A flag roundels (National Control Markers, or NCMs) or other suitable tokens such as the Convoy Nation Markers produced by HBG:

http://www.historicalboardgaming.com/HBG-Convoy-Nation-Markers-X5_p_1821.html

• The IPC value of each convoy is indicated by placing plastic chips under the convoy markers on the game map (one for each IPC).  The markers themselves have no IPC value; they simply denote the location and nationality of each convoy.  [To be determined : Give each convoy a standard value of 3 (meaning 3 grey chips), which seems to be the current preference?  In such a case, we could dispense with the “Max. Value” column of the setup charts.  Or give different convoys different values, perhaps as a reflection of the economic value of their ports of departure or some other factor?]

• The owner of a particular convoy may need to fulfil certain conditions to collect the bonus income generated by that convoy – for example, by holding the convoy’s port of departure.  These conditions are listed in the convoy setup charts [which still need to be developed].  [To be determined : Are there certain conditions under which one nation can take over the convoy routes of another nation, for instance in the (potentially) odd case of the Dutch East Indies convoys?  Regarding the DEI convoys, one point to consider is that the DEI are a net exporter of valuables such as oil, and that a DEI convoy therefore technically represents an outgoing convoy rather than an incoming one.  This raises the following question: to whom are the DEI supposedly shipping goods prior to their takeover in the Global 1940 game?  It can’t be to Holland because Holland is already an occupied country at the start of the game…so if it isn’t going to Holland, who is the “pre-DEI-takeover” recipient of the Dutch convoy bonus IPCs?  Black Elk proposed a couple of possible solutions, and based on his analysis my suggestion would be: that we assume that no DEI convoys exist prior to the takeover of the DEI, and that we then introduce a DEI convoy when the DEI is occupied; the convoy would be either Japanese or British or ANZAC, depending on who takes control of the DEI.  The draft setup charts alreday contain the notion that certain conditions might need to be fulfilled to operate a convoy, so an extension of that principle might be that the existence and the nationality of certain convoys is “conditional”.  Under Condition X, a particular convoy (perhaps better thought of here as a convoy route) is inactive; under Condition Y, it’s operational and owned by Nation A; under condition Z, it’s operational and owned by Nation B.  This system could be used outside the DEI too, but the DEI is a good example for discussion purposes.  Under conditions Y or Z, the convoy would be indicated on the map by the flag roundel (or HBG convoy marker) of Nations A or B respectively; under Condition X, an upside-down flag roundel (or upside-down HBG convoy marker) would denote the presence of an inactive convoy route.]

• The IPC value of a convoy is reduced when it suffers casualties as a result of enemy attack.  This reduced value is shown by removing the appropriate number of chips from under the convoy marker and by adjusting the income tracking charts accordingly.  [To be determined : Can convoys which have suffered casualties (and perhaps which have been completely destroyed) be built back up again to a maximum of their original value?  If yes, the details of the process need to be worked out, but one part that’s clear is that convoy markers would not be removed from the game map.  If no, then no replacement process details need to be worked out, and it’s clear that a convoy marker would be removed from the game map if all of its ships are destroyed, since there’s no point in marking the position of a destroyed convoy that isn’t coming back…unless perhaps we’re dealing with a “conditional convoy” as discussed above.]

• [Convoy attacks ('convoy raiding mechanism"), convoy defense (“convoy escort mechanism”), and combat-resolution mechanics: I haven’t attempted to summarize the state of discussion of these issues, for two reasons.  First, there’re still under very active discussion.  Two, as I’ve said previously I don’t have much any aptitude for these topics.  So my preference would be just to contribute some comments here and there on historical aspects of the issues as they’re debated by Black Elk and Baron and whoever else wants to chime in, if that sounds all right, and also to have more expert hands than mine write up the discussion-status summaries for those parts of the house rule.]

[CWO Marc]

@Baron:

About the Raiding mechanism, do you think this can be too complicated?

Any 1 Submarine raiding a Convoy Zone: auto destroy of all 3 IPCs.
The Merchant’s convoyed ships didn’t see them coming.

Any 1 surface warship (and up to 2 planes paired with Carrier) needs to make an attack roll against Merchant’s Convoy. Any hit makes for the destruction of 3 IPCs.

When there is warships defending the Convoy SZ,
attacking surface warship makes regular combat BUT the 3 IPCs Convoy is safe.
So any one can use a DD blocker to protect the Convoy SZ.

When Submarines are part of the battle, the attacker can choose to assign a Submarine’s hit to the Convoy, instead of an enemy warship chosen by the owner’s (as OOB combat rule for casualty).

This simply means that with Subs, the attacker can destroy enemy units AND the 3 IPCs Convoy.

In this case, the Convoy is played as an additional free hit (like these puts on Carrier or Battleship) without loosing a combat unit.

Just a comment: my concern isn’t so much whether this is too complicated or not, but whether it’s realistic for a convoy to be completely wiped out by a single attack.  I’d say it isn’t.  WWII convoys that suffered very high casualty levels (and fortunately for the Allies, such massive casualty levels were the exception rather than the rule) generally had their numbers whittled down over the course of several days of fighting by multiple attacks carried out by multiple attackers.  The so-called “wolf pack” sequence seen in the Humphrey Bogart movie “Action in the North Atlantic” is thrilling but completely unrealistic: it shows a huge swarm of U-boats cruising underwater in a large formation (almost like a fighter squadron), and it compresses into a five-minute battle (showing multiple cargo ships being torpedoed and multiple U-boats being blown apart by depth charges or rammed by destroyers) a level of carnage that, in real life, would typically have been spread over several hours or even days.  In WWII, if a convoy found itself in a hopeless situation against an overwhelming enemy force, the commodore might well opt to order the convoy to scatter – as was done in the Jervis Bay / Admiral Scheer confrontation, or with Arctic Convoy PQ17 – even though this was regarded as a desperate measure of last resort.

It think it would be more realistic to have the total destruction of a convoy only happen under two situations: in a single turn when there’s a massive strength advantage in favour of the attacker, or over several turns when the force ratios are more balanced (which would be a more typical situation).

[baron Münchhausen]

I was more talking in a game perspective, as your comment help me realize.
1 defenseless transport worth 7 IPCs.
No risk and no roll, so you destroy 7 IPCs.

For a 3 IPCs merchantmen’s transport, it shouldn’t be very different.

For now, I talk within OOB rules boundaries for everything else as a basic to find a workable Convoy raid mechanics.

Marc, I can’t disagree about your depiction of a Wolf-Pack raid against Convoy.
If it is possible to find a way to make partial success for raider I would prefer.
But we need to sweeten the jackpot or it becomes of no interest to risk or divert warships or subs from main combat strategies:
Or maybe it cannot go deeper into detailed depiction and stay a more abstract game mechanics but still giving the feel of Convoy Raid. IDK. 3 IPCs worth only 1 Infantry.
Sinking a single OOB 6 IPCs enemy’s Subs is a bigger price.
Clearing a 8 IPCs DD blocker can be a better and sound strategy than taking a risk to destroy 3 IPCs.

And there is no positive reward for the attacker unlike land TTs IPCs which will change from one hand to another.

Also, keeping unit On Station makes them very vulnerable to counter-attack since there are within 2 space range of the Capital’s Power.
It takes time (more than 1 turn) to reach such SZ for attacker.

Within OOB limits, the balance is a tough call and is put on a razor edge.
Maybe you need 2 chips of 3 IPCs per Convoy SZ to make it as valuable as the cheapest naval unit, at least.

But this can makes too much money: 2 Convoy SZs at 6 IPCs = 12 IPCs increase… and 3 Convoys SZs make 18 IPCs.

On the other hand, this could be a positive +3 which can becomes -3 IPCs if it has been hit twice. But such thing would require more book keeping and is far less straight forward…
So,  2 Convoy SZs at 3 IPCs = +6 to -6 IPCs increase… and 3 Convoys SZs make +9 to -9 IPCs.

---

I believe this 3 IPCs Convoy token should be replace every game round.
So, it must be destroyed each time to prevent a Power to receive such 3 IPCs bonus related to a given Convoy SZ.

I believe that a real Destroyer unit or more should be place in a SZ to represent the Convoy escorting warships.
Otherwise, if risk increase for attacker without any real enemy units defending the Convoy SZ, it becomes difficult to find some rewards for raiders:

On SBR, a bomber can do on IC much more damage than only 3 IPCs.
Also, it gives the opportunity to attack Fighters directly which would otherwise be place behind a pile of ground units.

[Black_Elk]

Well, the simplest and most familiar method would be to just say these convoys work exactly like the convoys of the Original A&A Europe game (1999.)

In that case, there was no specialized “convoy attack” or “convoy defense.” It wasn’t a combat per se, so much as a combat movement. In that game, if a convoy zone was defenseless (no protecting warships) then all the raider had to do was enter/pass through the zone to deny their opponent the cash. If their opponent left a ship in the zone to defend the convoy, then this ship had to be destroyed first, and any attacking warship that survived the engagement would then occupy the sz denying the cash to the opponent.

That’s the most basic National Convoy system I can think of. Of course, we could try to improve on it with additional elements, but if you wanted to keep things as simple as possible, it might be worth just using those rules as the base.

I would be concerned about allowing negative IPCs (-3 ipcs etc) back into the game, mainly because it just seems kind of bizarre to me. Allowing a “raider” to destroy more IPCs than the convoy is worth, is hard to explain, even as an abstraction. I can imagine a way it might be interpreted, but I can’t imagine a way to readily explain it without violating the whole “National” convoy idea. So for example, it might be that the USA is sending Convoys of goods to the UK… and any goods that get through are +X ipcs to UK, any goods destroyed are -X ipcs to USA. But already that just looks way more complicated than its worth.

I would much prefer to keep everything in positive integers. If +3 ipcs isn’t enough, then raise the value to +6 etc, rather than going negative. Otherwise you have fallen back into the model that has ipcs being destroyed (taken from the cash on hand and returned to bank) rather than one which just diminished the amount of IPCs you can collect in the first place, which is much simpler and less distorting (e.g. you can’t be raided enitrely out of play.)

I default to a gameplay rationale, as usual, I find something that I think would be fun for the gameplay, and then try to support it with the real world abstractions.
:-D

The whole point of creating a convoy system to begin with, in my view, is to attach IPC values directly to the Sea Zones in some way. Clearly this is an abstraction, even in real world terms. We’re not talking about fishermen pulling fish out of the sea, but rather the idea of a “Trade”, or National exchange, the concept that the same resources/goods can accrue in value, if you’re able to move them farther afield. In my suggested example, that’s what the +3 ipcs would represent, a bonus to the nation’s normal national production when it’s able to move across the sea.

In that respect I still think it is more fruitful to conceive of the convoy as a “shipping lane” rather than the actual ships/goods travelling along it. If you control the lane, it is possible to move the resources to a place where they have more value. If the lane is being contested, then you will lose that value (or at least some of that value), because now the logistics cost involved in defending/moving the goods will necessarily increase.

Keeping the broader gameplay in mind, the advantage of having convoys, is to encourage the purchase of more naval units. Just having more money in play (which the convoys would introduce) helps to facilitate this, but players are even more likely to buy ships, if that additional income is directly attached to a SZ rather than exclusively to land territories, as it is OOB, because then you need ships to disrupt it.

At every point along the way, you have to make a compromise. A&A is just too simplistic to model everything. It might be entirely conceivable for aircraft to sink a convoy vessel in the real world, and this surely happened in the war, but it’s worth considering whether the game really needs to model this? In A&A Europe (1999) it was not possible for Aircraft to disrupt convoy income, you had to have a ship. Not to suggest that we can’t improve on this, and somehow involve Air in the convoy disruption/defense, but just pointing out that it’s not strictly necessary.

I think there comes a point in these games, where the rules can get away from the gameplay enjoyment, if a mechanic is too complicated or if it’s application is too rare. It’s worth keeping in mind that players of the 1940/Global games have different expectations and more tolerance for complex rules, but for a game like 1942.2 I definitely favor simplicity. Put another way, it might be best to work out a bare bones system for 1942.2, and then build onto it for the 1940 games, if you want to add extra steps or nuances to the mechanics of it.

[CWO Marc]

Here are some thoughts on the latest points discussed.

First, I agree that the method used for handling convoys should be as simple as possible.  Or to put it another way: the basic house rule for handling convoys should be as simple as possible, and individual players can then introduce additional details if they want as supplementary house rule modifications of the basic house rule.  I also agree that “negative IPCs” sound problematic and are a hard thing to visualize.  I’d prefer to stick to the concept of a convoy being worth 3 IPCs when it’s at full strength, 2 or 1 IPCs when it’s suffered partial casualties, and 0 when it’s been completely destroyed.  Its value should not go above 3 or below 0.

It’s a valid point that the attacker needs an incentive to attack a convoy, but I’m not sure that the correct incentive would be a model in which the attacker can sink a whole convoy all at once, but in which the convoy automatically reappears on the next turn.  To me as an attacker, the automatic reappearance of the convoy would discourage me from bothering to attack it because, in effect, this would mean that I’d have to keep sinking the same convoy over and over again to keep its IPCs out of my opponent’s hands – a task which would tie down my valuable naval units, which I could perhaps use more profitably elsewhere for other purposes.  A further problem is that this model would not be realistic.  In real life, cargo ships that have been sunk by enemy attack don’t magically float back up to the surface and continue towards their destination; instead, replacement ships have to be built and launched and loaded and sent on their way across the seas, all of which takes time and money.  And to draw a parallel with land warfare (both in real life and on the A&A game map): when a territory gets conquered by an invader, the territory doesn’t automatically liberate itself after a set amount of time and the invader therefore doesn’t have to keep conquering it over and over again in order to keep it out of enemy hands.

To me, the biggest incentive to attack a convoy would actually be a model in which the convoy doesn’t automatically regenerate itself, and in which convoy losses therefore cause serious harm to my opponent.  In such a model, I wouldn’t be worried about whether I could or couldn’t knock out the whole convoy at once; any damage I inflicted, whether it be the loss of 1 or 2 or 3 IPCs by the convoy, would be worthwhile.

That being said, I think it would be a good idea if convoy losses could be replaced under certain circumstances, provided that this was handled in a way that’s realistic and that doesn’t remove the incentive for an attacker to attack a convoy.  I think the way to handle this would be as follows.

Remember that a convoy is a group of cargo ships: freighters, tankers and other merchantmen.  They’re represented in the house rule by a marker, but conceptually they still consist of ships; in a sense, the ships are really represented by the grey plastic chips under the convoy tokens.  (Perhaps more accurately, these chips represent columns of ships within a convoy, each column consisting of several vessels).  Regular A&A ships, such as naval transports, are units that can be purchased, and the cargo ships in the convoys could be thought of in the same way.  Each player starts the game with a specified number of convoys, which don’t have to be purchased – but if a player’s convoys starts taking casualties, he would be able to replace the lost cargo ships by buying replacement ones (in effect, by buying replacement grey poker chips).

There are, however, a few things that we’d need to figure out about this concept because it represents the process of building and launching replacement ships, loading them with cargo, and having them travel along their cargo route (which takes time and money in the real world).  I think there are basically three possible options for doing so:

1. A player acquires replacement cargo ships (poker chips) in the same way that other naval units are purchased: each poker chip costs $x (we’d need to figure out a fair price), it’s built at a coastal Industrial Complex, and it has to sail from there to its designated convoy location before it’s considered fully operational.  I think this would take too much time, and it would introduce too many confusing complications by having poker chips moving across the map.

2. A player buys replacement chips for $xxx – a much higher price than the cost of $x in option 1 – and gets to add the chips directly to the desired convoys, without any transit time.  This could work (though we’d once again have to figure out a fair price), but it’s not my preferred option.

3. A player buys replacement chips for $xx – let’s call these mid-priced cargo vessels – and adds the chips directly to the desired convoys…but he has to wait one full turn before doing so.  In effect, he skips a turn (meaning that he has to live with an under-sized convoy for a full turn) to represent symbolically the time it takes for the newly-built cargo ships to join the operational convoys.  This is my favourite option: it imposes a time delay in the replacement process (which is realistic), but the delay is of standard length (one turn)  and it does not involve any chips moving across the game map on their own.  As always, we’d have to figure out a fair price.

And on the issue of fair pricing: I think that the calculation of the replacement cost for convoy poker chips is probably the best way to find the right balance between the attacker and the defender of a convoy, while keeping the combat system itself very simple.  If we determine that the attacking and defense mechanisms for convoys provide too much incentive for the attacker, then the solution would be to lower the cost of the replacement chips.  If on the other hand we determine that the attacking and defense mechanisms for convoys provide too little incentive for the attacker, then the solution would be to increase the cost of the replacement chips. Adjusting this variable, rather than adjusting the attacking and defense mechanisms themselves, would allow us to come up with a convoy combat model that is simple and realistic and which doesn’t take up too much game time.

Now to switch to a different topic: convoy “conditions” or requirements, the topic whic is addressed in the right-hand column of my draft chart.  I’m thinking more and more that we do need to define operating conditions (at least in simple terms) for each convoy on the map.  The reason is that, conceptually, a convoy needs three things to operate: a port of departure (where the transported goods come from), a port of arrival (where the transported goods are going), and of course the actual ships in the convoy (the topic discussed in the paragraphs above).  Without all three components, convoys can’t operate in the real world – so the game should reflect this.

Fortunately, modeling this in A&A both simply and realistically would be pretty straightforward.  For each convoy, we’d simply need to specify one or more ports of departure and one or more ports of destination, and require that the convoy owner (or one of his coalition partners) control one or more of the specified territories at each end of the convoy route in order to collect his bonus IPCs.  The departures and arrivals could be tied to a single specific territory (for example Java in Global 1940, which would be a single port of departure) or to a multi-territory area (for example “United Kingdom or Scotland”, which would be an either/or port of arrival in Global 1940, and which we could designate collectively as “British Isles”).

As an added refinement: if we assume that all convoys have a standard maximum value of 3 IPCs, we could retitle the second column in my draft chart as “Convoy Name”.  This would be kind of cool, and also a useful memory aid in game play.  In WWII, convoy routes sometimes had names and individual convoys usually had code numbers.  These designations sometimes referred to ports of departure or ports of arrival – for instance the Gibraltar run, the Murmansk run, the HX convoys that departed from Halifax, and the SC convoys that departed from Sidney, Cape Breton.  So we could give each convoy route its own name, as well as specified operating conditions.

Note, by the way, that an opponent would actually have multiple ways to shut down a convoy: from the sea, by sinking it, or from the land, by conquering either its port of departure or its port of arrival.  A land power like Germany, therefore, might be more inclined to try to shut down a convoy route “from the land” (by territorial conquest), while a naval power like Japan might be more inclined to shut down a convoy route “from the sea” (by using parts of its fleet).  As a bonus, this would nicely illustrate some of the relationships that exist between land warfare and naval warfare.

[CWO Marc]

Here’s the second version of the working chart:

Blank Convoy Chart Global 1940 v.2.doc

[baron Münchhausen]

There is many things to comment, but for now I will stay focus on the mechanics of Subs raiding.

We can say that an enemy warship needs only to pass through a Convoy SZ to destroy at least 1 IPC token.
This will make attacking warships less sitting duck of them if they can choose where they finish their move.
This also imply that it would be possible to pass through a Convoy SZ to attack another one, or enemy’s warships.

I would prefer that Subs have an advantage over surface warships.
Something like each surface warship can only sink 1 IPC token at a time.
Submarines can sink 2 IPCs token at a time. I can agree with the idea that destroyed token must be replaced by paying an additional fee during the purchase and repair phase.
I suggest a simple 1 IPC fee per token. This would be similar to the IPC payed on damaged IC.
That way, when a 6 IPCs Sub is passing through a 4 IPCs Convoy SZ,
the owner will lost 2 IPCs (still earning 2 IPCs) and it will cost another 2 IPCs to put 2 new 1 IPC tokens on board for his next turn.
So this is an overall expense of 4 IPCs.

Surface vessel wouldn’t be able to attack Convoy if any escorting warships is with them.
When Destroyer are protecting such Convoy SZ,
I still prefer to let the attacker choose whether Submarines’ hits are allocated to Convoy token or Destroyer.
But, once the escorting warships are all destroyed, the naval battle is over and no more token can be destroyed.
That way, Convoy attack can be prioritize over warships (as it was the case in Atlantic u-boat war)

I would be partisan of various Convoy SZ values such as 2 IPCs, 4 IPCs and 6 IPCs.
For 1942.2, German’s Convoy SZ near Norway should be at 2 IPCs (Norway worth only 2 IPCs) while Baltic Convoy (iron trade with Sweden) should be at 6 IPCs.
Italy’s in Med could be at 4 IPCs.

[Black_Elk]

Some great feedback and great charts too! I’m stuck at work or I’d write more, but just wanted to chime in real quick like while I’m on my break.
:-D

Taking it back to the Europe 1999 convoy rules, just for reference, its not so much that the convoys there replenished automatically, instead the owner of the convoy (the nation to which it is attached) must control it during their collect income phase. If the enemy takes it you can flip the roundel to indicate that the convoy is currently inactive, and must be recovered by yourself or your team before you get the cash.

Now in Europe 1999, all these convoys are in sea zones that would be otherwise pretty undesirable locations to have your units. They are stuck in the midway points, often between two important sea zones, but not particularly important by themselves, except for the convoy cash. So what generally happens is you’ll see players making a series of “passes” or “sweeps” across the convoy sea zone, first by the enemy to disrupt the convoy cash, then by the original owner/team to try and recover it. Actual combats for control of the convoy in early rounds were rare. Usually the convoy was designed as a way for the Allied economic advantage to become inevitable after the first few rounds.

In other words, the whole unit set up and location of convoys on the map was specifically designed such that Germany could only “disrupt” the convoy cash initially… First by doing these low risk “passes.” And perhaps they can keep this up for a little while. But within a few rounds, the Allies can position units to defend the convoy zones. At this point the German player can no longer disrupt the convoy at no risk just by “sweeping across them”, but instead has to start throwing subs into attacks. Here the control of the convoy is sort of like a bonus on top of destroying the defensive ships (really you just want to take a crack at the ships to whittle away the opponents TUV, but the convoy cash denied to the opponent if you win is there as an extra draw.) In the end though, control of the convoy is usually secured, and it is only at that point when the IPCs are a dependable part of your income.

Its kind of hard to describe without a visual, so here’s a glance at the tripleA map. I’m partial to that map, since I drew the baseline for it in early days hehe…

You can see down below (images attached) that the starting German U-boats were positioned to steal the convoy income away from the Allies, during the first round. In the second round, Allies are usually able to recover a couple of these, whereas most will still be under German control. By the third round the Allies will usually drive the U-Boats back making it harder for Axis to deny the Allies this income, and that’s when the Allied economic advantage will usually start to accelerate and really kick into high gear.

TripleA shows the starting Allied Roundels, being replaced by a German roundel, while the computer tracks the drop in British/American production. But this is a confusing system in a face to face game where the original owner/value of the convoy zone is not drawn directly on the map (as it was in Europe 1999). In a FtF game where that information is not drawn on the map, the best approach would be to use roundels for the original owner/value of the convoy and just flip the roundel (but leave it where it is) if the convoy is “disrupted” ie. taken over by the enemy. That way there is no confusion about which nation collects the income for the zone. Once the roundel is dropped, it stays the where it is, since this indicates “original” ownership.

This was an all or nothing conception of the Convoy Zones, where the British or Americans would lose the whole value of their convoy zone if the Germans disrupted it. It also had them at varying IPC values a 3, a 5, or 6 etc…

If you wanted to replicate that system, but in a game where this information is not already drawn on the physical map (e.g. 1942.2), then the roundel markers would definitely seem to be the easiest method. But I’m getting that the Europe 1999 system would be insufficient to create enough interest for players to go through the trouble of adopting our new HR convoy system. What we really want is a way to improve on Europe 1999 (using it as a model, rather than the Global convoy system) and then add in some elements of excitement, while still keeping things as simple as possible.

So say you wanted to make the values of each convoy zone variable…
and you want this information readable at a glance (without drawing on the map)…

As long each sea zone only contains Convoys from a single Nation (e.g only one type of Nation’s roundel), and as long as all roundels have a universal set value (whatever that is determined to be 1 ipc, 2 ipcs, 3 ipcs?) then you could just place multiple roundels in a zone to indicate the value of the convoy.

Lets explore a base 2 system.

For example
1 roundel = 2 convoys, with 2 gray chips, worth 2 ipcs
2 roundels = 4 convoys, with 4 gray chips, worth 4 ipcs
3 roundels = 6 convoys, with 6 grey chips, worth 6 ipcs

In any given sea zone, all the roundels will belong to the same nation, the original owner, (this is a National Convoy system after all) but by breaking them apart into separate roundels you have an easy way to track the totals at a glance. Again, if you wanted a sea zone worth 6 ipcs, you would place 3 National roundels (each of them representing a convoy worth 2 ipcs = 2 gray chips)

‘Why is this better than using a single roundel with 6 gray chips beneath it for the whole zone?’

Because, in a game where convoys can vary in total value, then as soon as the enemy starts knocking off chips, players might forget what their convoy is worth. They’d have to go back and re-read the set up charts. If you allow for replacement chips, then this confusion might increase during the course of play. Sure players might eventually commit it all to memory, but why force that? This method provides a ready way to know exactly what a given convoy zone is worth (its potential Max value) at any time.

Then you could allow them to be a purchasable unit, and a unit that can be “destroyed” in a way that makes a bit more sense to me. For example… The convoy takes 2 hits, and then the Roundel itself is “exposed”! If the raiding enemy nabs the third hit, the roundel is flipped and the convoy is considered “disrupted”. Now the roundel itself is not worth any IPCs, it is not removed.  Here’s the kicker, the Convoy does not automatically repair, instead you can “repair” 2 convoy chips for the cost of 1 ipc! This restores the chips, if the National Roundel is still upright.

If the roundel is flipped, perhaps it costs 3 ipcs, to reactive.

Also, like on Marc’s charts, if one of the conditions is not met for the convoy, like the port of origin or destination territory is captured, then you flip the roundel upside down as well, to indicate that.

I think something like this would be necessary to make a purchase mechanic work, since the whole point of the Convoy unit itself is just as a means for the player to gain more IPCs at collect income.

The convoy chip is just an ipc in waiting. It has no cool combat value, or any other advantages like the other units do, so its kind of a weird thing to pay for, unless as Baron noted, the value for the investment is pretty good. If you have to purchase or spend anything at all in IPCs, to make use of these Convoys, the net benefit in IPCs has to be a lot greater (like twice the value gained), as an incentive to spend that money for convoys rather than on units. Hence the 2 for 1 repair, if the roundel is still upright. You could cap the total number of Convoy roundels that can exist in any one zone. Say at 3 total roundels for your nation.

Then if you like, the player could opt to invest in more Convoys, but only up to that Max value (3 roundels = 6 ipcs, 6 gray chips.)

That’s probably the simplest way I can think of to make a Convoy that is somehow “purchasable,” or which can be diminished by the enemy through some kind of attrition. You could pick any number for the max roundels, 3, or 4, or 6, whatever. The idea is that there is some ceiling or upper limit to the amount a nation can invest in convoys.

Convoys can only exist in the designated “Convoy Zones.” They are represented by the National Roundels, with a consistent value (always worth the same number of IPCs/chips.) If you cap the total number of Convoys per zone, and fix their possible locations, it is conceivable that you could make the Convoy Roundel itself purchasable, so you can add more to a zone over time, but the existing convoys are never totally destroyed, just flipped upside down.

Would something like that make sense?

Then you could try to introduce a combat element into the thing, instead of just a movement phenomenon like the Europe 1999 system. Its still possible to make each convoy worth 3 instead of 2, but then I’m not sure how the purchasing would look, since you can’t really do the "2 for " simple repair thing. Also, if the convoy Roundel is worth 2 chips, you can create a bit more variety in the total ipc values for these zones… At 2 ipcs or 4 ipcs or 6 ipcs for example = slightly worse, slightly better, or twice as good, as the replacement cost of a single infantry unit. 3 ipc convoys couldn’t work here, since each roundel would be worth 2.

If you do the same thing with base 3 ipcs per roundel rather than 2, (like I suggested earlier) you’d have to work with 3, 6, or 9 for the total value of convoys, which might be too much money overall at the high end, given how many zones we want to include?

With a 2 chip per roundel model, maybe you could say that a surface warship only clips one chip at a pass, whereas a sub clips both? Or maybe the sub removes a chip from each roundel it passes, whereas surface warships can only remove chips from a single roundel? Something like that to privilege subs this role?

Also, since the replacement cost can’t be 1 for 1 (the investment would be a wash with no benefit for the investment) would a replacement cost of 2 for 1 be worth it? Using a 2 ipc model, that would mean the convoy owner could repair a loss of 2 chips for the same cost as a loss of only 1 chip. Might that effect the Raiders calculus, as a disincentive to raiding with warships?

I’m waffling when it comes to the set ipc values per roundel. I can see an argument for 2 chips and 3 chips, but it depends on whether you want to give the roundel itself a “hit” and do the whole flipping upside down, restoring to upright for an additional cost idea. I think 2 might be better for a simple “pass/sweep” mechanic, but 3 might be better if you wanted to make a roll for damage mechanic. Not sure though, any thoughts?

All my discussions above assumed 1 gray chip = 1 ipc, though I suppose you could make 1 chip worth 2 ipcs if you wanted. The only thing to keep in mind is how much total income you want to introduce into the game. In my mind it needs to be workable in 1942.2 to have any real shot of adoption, whether in the older world scale games like Classic/Revised/AA50, or the newer 1940 games. If it works and is enjoyable in 1942.2 that would be proof of concept for me. This places some constraints on the total money we can introduce I would think. I would say something like half of the normal starting income, for each nation via convoys, otherwise it could produce out of control spams, and too many total units in an average game.

[CWO Marc]

I like the idea of convoy value being indicated by marking a sea zone with multiple roundels (all belonging to a single power) without using any poker chips rather than marking the SZ with  a single roundel combined with one or more poker chips.  As you say, this would allow the situation on the map to be understood at a glance at any time, without lifting roundels to count chips and without consulting setup charts.  This is good, because it fits with the aim of having a system that’s as simple and clear as possible.

By the same principle, however, I do have one reservations about this part:

Then you could allow them to be a purchasable unit, and a unit that can be “destroyed” in a way that makes a bit more sense to me. For example… The convoy takes 2 hits, and then the Roundel itself is “exposed”! If the raiding enemy nabs the third hit, the roundel is flipped and the convoy is considered “disrupted”. Now the roundel itself is not worth any IPCs, it is not removed.  Here’s the kicker, the Convoy does not automatically repair, instead you can “repair” 2 convoy chips for the cost of 1 ipc! This restores the chips, if the National Roundel is still upright. If the roundel is flipped, perhaps it costs 3 ipcs, to reactive.

The reservation is that, if I understand the above paragraph correctly, a convoy’s status has four possible states:

• 0 hits (fully operational status)
• 1 hit ( … status?)
• 2 hits (“exposed”)
• 3 hits (“disrupted”)

The last state is represented clearly enough by a flipped roundel, so that’s fine…but the other three states are all represented by an upright roundel, which is confusing and which runs counter to the “understandable-at-a-glance” principle.  The two possible options for dealing with this problem would be:

• Have just two states: active (=upright) or disrupted (=flipped).  This would have the advantage  of being simple, but it would disallow intermediate-level damage.

• Having three or four states, which would require some sort of means to represent the intermediate states.  Note that in A&A battleships have three possible states: on the board and upright, on the board and tipped on their side, or off the board completely.  This feature of battleships suggests the following solution.  If we supplemented each convoy token with a transport ship sculpt (as was originally discussed), we could have the following status representations:

• 0 hits (normal status) – upright roundel + upright sculpt

• 1 hit ( … status?) – upright roundel + sculpt on its side

• 2 hits (“exposed”) – upright roundel + no sculpt

• 3 hits (“disrupted”) – flipped roundel + no sculpt

On a different topic: we’ll need to think about what the multiple roundels in one SZ represent conceptually, because it has implications for the damage / disruption mechanics of the house rule.  We need to analyze this because in WWII  multiple separate convoys did not sail together as a group.  In other words, you’d never have such a thing as a “three-convoy formation.”  Instead, you’d either have three separate small convoys, or one single large convoy.  There were advantage and disadvantages to each approach.  The advantage which single large convoys had over multiple small ones was that – for reasons related to the geometry of rectangular formations of ships – you could double the size of a convoy (increasing it by 100%) without having to double the size of the escorting force (increasing it by about 50% might suffice).  On the other hand, large convoys took more time to form up than small ones – so if there was a pressing need for certain goods to be delivered ASAP, they might be sent right away in a small convoy rather than waiting for enough ships to assemble to form a large one.

On the game map, three roundels in one SZ could stand either for three separate convoys, or for a single convoy three times larger than a “basic” one-roundel convoy.  The “three separate convoys” method would intuitively be easier to grasp from the visuals on the game map (three separate tokens), but it would probably imply that the three separate convoys would have to be treated separately for combat or disruption purposes.  The reason is that separate convoys in WWII really were separate: they were not close enough to support each other for defensive purposes, and they were not close enough for a single attacker to attack them all at once.

So I guess the correct model to use would ultimately depend on what kind of combat / disruption mechanism we use.  I don’t have any immediate thoughts on the subject (since I’m busy with something at the moment), but later on today I hope to have time to think about these issues and write some comments on them.

[CWO Marc]

Here are some additional thoughts on two issues which Black Elk raised: how many bonus IPCs a player should be able to collect from the convoy(s) he has in a given SZ, and the matter of “disruption passes” versus actual combat involving a convoy.

Black Elk’s suggestion was that, for 1942.2, the total income delivered by all the convoys at full strength should be about one-half of the normal total starting income of the various powers.  This sounds about right to me.  The precise final amount might vary a bit from this proposal, but the basic principle, in my opinion, ought to be that the convoys should add enough extra money to make the game more interesting, but not such a huge amount of money that they have two unwanted effects: distorting the purchasing abilities of the various powers in a way that would unbalance the game, and making the convoys so important economically that they become a critical military objective on an equal footing with the land war.  The convoys, to use a food analogy, should be an interesting side-dish added to the dinner table, not a fundamental change to the main course itself.

Working, therefore, from the principle that convoys should not be excessively important, I agree that it might be a good idea for the anti-convoy mechanism used by the attacker to be a simple and somewhat abstract one (“disruption”, a concept that could be explained or rationalized in various ways if we decide to go that route), since there’s no point in applying a complex combat mechanism to a game element that’s only supposed to be of medium importance.

The three options as I see them are:

1. Have only one anti-convoy mechanism available: disruption.  The details would need to be worked out, but the effects would be fairly abstract.

2. Have only one anti-convoy mechanism available: combat.  This would refer to (roughly) the same type of combat that is used elsewhere in A&A, but it would (potentially) involve three types of forces: the attacking warships (and planes), the defending warships (and planes), and the merchant ships that the two sides are fighting over.

3. Have two anti-convoy mechanisms available: disruption or combat (but presumably not both simultaneously), preferably set up in such a way that disruption would be the method used most often and combat would be the exception.

Option 1 would be the simplest one.  Option 2 would imply that every anti-convoy operation would be a full-blown battle, which would probably slow down and weigh down the game.  Option 3, if it could be somehow calibrated in the way I described, sounds like it might be the optimal mix.

[baron Münchhausen]

You put a lot to think about gentlemen.
It’s great!
I wonder if the simple flip of Country Markers could be a solution to represent a Convoy. No need for grey token.

1 Country marker worth 2 IPCs to collect during owner’s Income phase.
(No need to move them, just count which one is face up in the SZ.)

1 Country marker cost 1 IPC to flip on the upright side (because it was put downward after a successful Convoy Disruption/Raid) at the end of the Collect Income phase when the IPCs are calculated. But the repair was paid for on owner’s Purchase and repair Phase.
No waiting until the next player’s turn between repair and flipping, no book keeping: just a flip.
You can put a few tokens in the mobilization zone to indicate that the owner paid for the convoy repair.
In addition, an upright marker makes for an immediate target for enemy during the next game round.
All is done at the owner’s turn. Except, it is just slightly different than buying small transport ships.

1 Convoy SZ can have 1, 2 or 3 Country markers.
If a Convoy SZ have only 1 or 2 Country markers, the Nation owning the Convoy SZ can purchase additional Convoy (representing additional seaport infrastructures & Convoy logistics, Merchant’s ships and cargo) up to a maximum of 3 markers in this given Convoy SZ.
1 Country marker cost 2 IPCs to buy when adding one in a less than Maximum Convoy SZ.

1 Sub can destroy 2 Convoys (2 Country markers) by moving through this SZ during combat move or attacking in the SZ.
Simply flip face downward 2 markers.
1 Battleship can destroy 2 Convoys (2 Country markers) also. Same condition as Sub.

Each Destroyer or each Cruiser can only destroy 1 Convoy each (1 Country marker flip down). Same condition as Sub.
Undamaged Carrier can destroy 1 Convoy per Fighter (or TacB) paired with which can land on the aircraft (up to 2 max per Carrier), if they land on the Carrier which stay in the Convoy SZ or pass through this SZ.

2 Tactical Bombers (G40 but not 1942.2) based on land can destroy 1 Convoy (1 Country marker). Need to attack the Convoy SZ.
2 Fighters (1942.2 not G40)  based on land can destroy 1 Convoy (1 Country marker). Need to attack the Convoy SZ.
2 Strategic bombers can destroy 1 Convoy (1 Country marker). Need to attack the Convoy SZ.
It takes twice units because Convoy targets are difficult to find and planes have a limited time to spent over Convoy for attack.

In February 1941, the Oberkommando der Luftwaffe (OKL) was ordered by Adolf Hitler to form a naval air command to support the German Kriegsmarine’s U-boat operations in the Battle of the Atlantic.[1] Though reluctant, the commander-in-chief of the Luftwaffe, Hermann Goering, agreed to the formation of the specialised naval command which would remain under the operational control of the Luftwaffe. It was subordinated to Luftflotte 3, commanded by Hugo Sperrle.[1] The command had jurisdiction over all Luftwaffe operations in the Atlantic and supported German surface raiders and submarines attacking Western Allied shipping in the Atlantic Ocean, English Channel and Irish Sea. The organisation’s first commanding officer was Martin Harlinghausen.

The command flew in action and achieved considerable success in 1941. British shipping losses rose. Prime Minister Winston Churchill referred to Fliegerfuhrer Atlantik and its main weapon of war, the Focke-Wulf Fw 200 Condor, as the “scourge of the Atlantic”. Nevertheless, at the close of that year British and Allied countermeasures tamed the threat from long-range German aircraft. As the battles in the Atlantic intensified in 1942 and 1943 the command made continuous demands for aircraft and crews. Now engaged heavily in other theatres, the Luftwaffe could not afford the resources for Atlantic operations.

http://en.wikipedia.org/wiki/Fliegerführer_Atlantik

Maybe land-based airplanes against Convoy can be played as an attack on IC with less results?
Before sinking any Convoy (flipping a Country marker), each land-based plane must submit to 1@1 AA gun fire from AA convoy defense.
Then,
1 Tactical Bombers based on land can destroy 1 Convoy (1 Country marker). Need to attack the Convoy SZ.
1 Fighter based on land can destroy 1 Convoy (1 Country marker). Need to attack the Convoy SZ.
1 Strategic bomber can destroy 1 Convoy (1 Country marker). Need to attack the Convoy SZ.

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Convoy Disruption in an undefended Convoy SZ:
Warships (Subs, DDs, Cruisers, Carriers, BBs) need only to pass through an undefended SZ,
Planes need to attack directly this Convoy SZ, and, after combat, planes paired to the Carrier must land on this particular Carrier which pass through the Convoy SZ.

Convoy Disruption in a defended Convoy SZ:
When Surface warships (DDs, Cruisers, Carriers and BBs) or planes are attacking any escorting warships in a Convoy SZ, it is a regular combat.
All the Convoys are considered safely guarded by escorting warships. No country marker is flip upside down.

If any Submarine is part of a Naval combat in a Convoy SZ, the attacker can decide to destroy Convoy.
Any attacking Submarines’ hit can be allocated on Convoy, and 1 hit destroy 2 Convoys (2 Country markers are flip down).
(So, when Convoy are protected, Subs must get a successful roll to destroy them.)

However, when all defending escorting warships are sunk, the remaining Convoy stay on the board (no more country marker can be flip down).

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I was writing down my post, Marc, as you post yours.
I believe my suggestion fall under your option 3 category.