P. 29 under Destroyer - “…if a destroyer is along the battle strip, it cancels the Submersible, Surprise Strike, and Cannot Be Hit By Air Units unit characteristics of all ENEMY submarines in that battle.” Doesn’t say it cancels out friendly submarines’ abilities in those areas…
P. 30 under Submarine - “When attacking or defending, hits scored by air units cannot be assigned to submarines unless there is a destroyer that is FRIENDLY to the air units in the battle.”
While I can see where one could construe that it means that the presence of a destroyer allows hits to be assigned to friendly or enemy submarines, I don’t believe that this is the intent of the sentence. “Air units” in this context means either attacking air units with a DD friendly, or defending air units with a DD friendly.
Example: US Carrier, 2 planes, cruiser, and sub attacks Japanese carrier, 2 planes, DD, and sub. While DEFENDING, both Japanese planes hit. Because of the presence of the Japanese DD, the American sub can be taken as a casualty. That is an example of an air unit DEFENDING with the presence of a FRIENDLY DD. If the American planes hit, the hits must be assigned to surface ships because there is no FRIENDLY DD.
Let me use my teacher English and parse the rule: “When attacking or defending, hits scored by air units (that are attacking or being attacked) cannot be assigned to submarines unless there is a destroyer that is FRIENDLY to the air units (that scored hits) in the battle.” We are talking about hits scored by air units in this sentence. When referred back to later in the sentence for the friendly DD exception, the air units referred to are the same air units at the beginning of the sentence that scored hits.
The rule must mean enemy subs. If I read the rule the way it is written, a hit scored by an air unit is assigned by the power that receives it. So if I am the American player in the above example with both Japanese planes hitting, I assign two hits. Because of the Japanese destroyer friendly to the Japanese planes that hit, hits can be assigned by the American player to the American submarine. The Japanese would not assign those hits to their own submarine. Conversely, if the American planes hit, the Japanese player cannot assign air unit hits to their sub because there is not a destroyer friendly to the American planes doing the hitting.
Thinking of it in a practical sense, how could the presence of say, an American destroyer allow Luftwaffe units to see American submarines under the water and sink them? That would be highly treasonous if the Americans were helping the Germans kill US subs. What is clear to me is that if you are attacking subs with planes, you cannot hit them without a friendly destroyer to sight them in for you.
P. 30 under Submarine - “When attacking or defending, submarines cannot hit air units.” Pretty black and white to me.