Noob Mistake... help.
 

While encountering an enemy, the game put up a multiple choice box, I chose dive to periscope depth. There was also a small checkbox for making it the default action, which like an idiot I checked.
I ended up chasing a merchant ship and the game went to periscope depth but I was unable to catch up to the merchant submerged and couldn't surface as long as there was contact! :(
I haven't been able to find a way to turn off the default action. Do I start another career or is there another way? Thanx!

The box should re-appear when you begin your next patrol.

Nope, exit the game, reload the save game, the DEFAULT reaction is lost - your prior mistake, and THEN you proceed to put them on the bottom where them dirt bags belong.

It is NOT a forever thing.

Just exit and rejoin. The DEFAULT action is only for your preferred game action until you exit or reload a saved game.

If you want a forever nightmare thing, reply to a Sailor Steve post. It's worse than your worst nightmare. :).

He [Sailor Steve] is known to hide a nuclear bomb in a coconut shell on Gilligan's Island and wear Ginger's clothes - now and then.

Watch out for that guy. He hides out in SH III stuff - mainly - just a heads up to keep you pure and innocent.

Now, get out there and sink them s.o.b.'s.

Whew... Thanx!! for the replies, much appreciated!!
:)