I read this on page 32-33 of Pacific 1940:
Remember that hostile sea zones contain enemy units, but that for purposes of determining the status of a sea-zone, submarines and transports are ignored.
A transport can load and offload units without moving from the friendly sea zone it’s in (this is known as “bridging”).
From my little understanding of the situation, the attacker could have ignored the sub (even with a DD escorting the transport) and go directly offloading the transport. In this case, their is no battle in the SZ and, hence, no possibility to scramble a defending plane.
I’m I right?
As a complementary on p. 32:
Doesn’t Block Enemy Movement: The “stealth” ability of submarines also allows ships to ignore their presence.
I just read that scramble can occur even when no friendly ship is present in the SZ.
So it means that the plane can defend the SZ.
But what happen if the attacker just want to make an amphibious assault and ignored the sub?
Is their only the scrambling plane which can roll for defense?
Or is it a case where it is the scrambling plane which “awake” the friendly sub in the SZ and make it a part of the battle?