[magic452]

Sounds like you got it pretty much figured out to me.

A O'kane surface radar attack looks to be in order.
O'kane is pretty accurate from 3000 + yards, I'd go for that.
Fire six and beet feet at flank to clear the zone before you are forced to dive.
May well have a thermal at >200 feet and heavy seas should give you a good chance against the escorts.

Remember that radar sweeps are 30 seconds and allow for that when you fire.
Plot the targets you want every sweep and you will have a good idea when to shoot. you'll probably have to settle for maybe two targets as shooting off radar will cost some accuracy.

A sonar attack would be good if you had a little more water but under these circumstances you'll want to be surfaced and able to put some flank speed distance between you and the escorts.

Strike while the iron is hot, good weather and 200+ feet of water is not a good mix.

Magic