I swim on the surface until I get there, dive quickly, plunder, up to the surface as quick as I can and swim away. They are faster than you underwater but you swim faster on the surface, take advantage of it.

I'll give it a shot.
So far, when my guy is hit, he's stunned for several seconds, during which time the drowner comes back and hits him again..... resulting in perma stun. :-(

That is, unless there's buildings underwater... that one was easy enough to get away from.

I believe you can only use the crossbow underwater.

It sounds stupid but you should use crossbow.Or you can go by boat and do the things quickly.

I'd call the crossbow "situational" as a weapon. It just so happens that taking out drowners underwater is one of the situations it's best used in.

I'll whine that one-shotting a drowner underwater with it is not "realistic," but since you're otherwise crippled combat-wise underwater...

I'll try it.

Thanks. :-)