Originally posted by Faceplant8:

I did the log out / log in trick, and it ALMOST worked. Used 300 stamina and 100 health, and died as I was reaching for the ladder! :-(

You have to keep doing it.

1) Stop swimming just before you run out of stamina.
2) Log out.
3) Immediately log back in.
4) Profit (stamina-wise)!
5) Resume swimming.
6) Goto 1