Can you ignore subs during an unescorted amphibious assault?

Thanks for your reply. Makes perfect sense.

OK that helps!

@Battlingmaxo:

…
I would like to point out that if you don’t have a destroyer in you attacking force the defender may choose to  submerge the subs in which casew you have your desired attack…ti piace?

I know, I know… Yeah, I like it, but I would prefer if I could choose… ;)

Sorry about that…I don’t know what I was thinking when I posted. The dd would obviously cancel the sub’s special abilities.  Thanks for the clarification and reminder.

It is a lot more complicated than the first glance.  I have been testing out different fleets fighting against each other, and it really seems like once fleets get big, destroyers are a major liability. 
If the enemy has a good number of subs, along with some planes or high value ships, then the you would be better off without any destroyers. 
So when is it good to have a destroyer?  If the enemy has few or no high value ships and few or no planes, then you will want the destroyer to negate the subs first strike ability. (or if the engagement is very small, like 1-4 units total, you may want it to make sure you are just outright killed).
So in other words, avoid building destroyers until you see what your enemy is building for a couple turns.  And most likely you should never build them in the pacific.

thx Kang,

Where do you live? If you are in/near Holland, you can try www.spellenenzo.nl, they sell it for 25 euro cheaper.

@Romulus:

But subs, as TRNs, can not stall because they may be ignored by other surface ships that may treat the sea zone with subs within as friendly or am I wrong?

You’re not wrong.

Subs submerge before any dice are rolled, attacker first then defender.  At the time the USA player rolled his hits, the decision should have already been made and acted upon.