THat population is certainly higher than Zero. I can name the Narwhal, for one, as a ship which was positively ID'ed as hostile before engaged.
Please do research before responding to me, I do mine before I post.
BZZZT!
Narwhal was a SUBMARINE, and was engaged by helicopters, not by fast-movers. And it was known that ANY submarine operating in the immediate vicinity of the British task force was hostile (that maritime exclusion zone thingie again).