Lets be honest here, Sea Lion is a cat and mouse game. Germany signals to the UK player that I’ll do Sea Lion if you don’t hedge against it by buying 6 Inf and 1 Ftr on UK1. As a German player, I want you to turtle. I don’t want a carrier on top of 2 Destroyers and a Cruiser with 4 fighters scrambling over it before I make my second purchase.
So, I’ll buy enough navy to make you play honest and not try to land in Europe all by your lonesome before the Americans arrive to save your ass. Those ships on G1 pay dividends for a couple rounds, and maybe I’ll augment them with a few subs to keep you worried about my Air Force swinging over the top of my navy and subs if you expose your Navy too early. After that, those ships I bought on G1 can be scuttled, they really aren’t going to be stopping a US landing, and they are just fodder to an ever growing RAF thats just waiting for carriers to land on to seize control of the English Channel. In the end, that Navy buys me another round in the early / mid game before you can threaten landing on W.Germany and ruin my Major Complex.
If you are playing against someone who ignores your Sea Lion threat, you continue with the purchase on G2 and get those TT out. As a German player, you REALLY don’t want to buy them, but if the UK insists on building a minor in Egypt, putting ships off of Canada or anything other than playing turtle you’re obligated to at least make it a reality you will be sacking London by flying a SBR and turning off that industrial complex to limit the units pouring out of it. As a German player, this is the least beneficial play, but you’re obligated to turn London off and possibly for good in the following rounds. You’re hoping Russia was expecting an all out blitz and played defensive on R1, backed off and purchased artillery for a potential counter attack, but if those Reds are in cahoots with those tea drinking Brits and they staged it you’ve gotten Germany caught between the hammer and the Anvil.
The problem with spending all those IPC on a slew of TT is that you’ve effectively severed the head or the spear in less tanks or the shaft of the spear in one less purchase round of 10 Mechs for fodder. Even diverting TT and INF to land amphibiously is less than opportune for Germany - you could have gotten those same INF to the same position for a G3 attack on Russia without the TT by simply stepping from Berlin to Warsaw on G1. So, what to think about?
Unfortunately, once you have those TT and SBR’d, UK is likely going to repair and do everything she can to defend London. This is the gambit both sides play. Can you take London without losing your aircraft? How many units do you need to keep the United States from reclaiming it right away? Will you lose your transports, stranding anything that ends up surviving? Are the Americans in a position to take your navy out with bombers? Can you hold off the Russians? Are you SURE? The Russians can be pretty solid on the offensive and Poland is the only thing between Berlin, a Red Europe and a GG.
Its a ballet that you have to play, and a wise player from the UK forces a German player to start one way, and then forces the Nazis a different way when a course reversal is less than opportune. This is what Sea Lion is.
So, how do I play? I threaten Sea Lion by purchasing a CV, DD and SS on G1. I can buy enough TT on G2 to take London if the UK player plays very loose. Generally UK plays a conservative 6INF 1FTR, so I abandon Sea Lion and G2 is a combination of Armor and Mech as I prepare to move on Russia on G3. I think G2 advance on Russia exposes my starting INF stack too much. I could change that by going all out ground purchases on G1 and not threatening Sea Lion, but I’ll be diverting resources on rounds 3, 4 and 5 to deal with the RAF and the Royal Navy if I didn’t purchase those ships on G1. I’d rather have an uninterrupted stream of Mech / Armor advancing during those rounds and replacing losses for multiple consecutive rounds than stranding a stack of Armor with no fodder in front of them and facing a choice to retreat, delay or sacrifice them.
Sea Lion, in my experience is reserved for use against UK players that don’t know what they are doing yet, or one who completely invites it on purpose.