A crew Where no one can swim is the final antagonist.
Well written Oda.
Very convenient way to deal with them! Just let them all drown!
Law vs BB is a great setup in this regard too as his crew are naval specialists, especially underwater too.
Imagine if BB didn't have Pegasus via Stronger and Van Augers warping ability? I'm surprised Kuzan wasn't there to utterly fuck over Law and his crew with his ice powers ofc but being an (ex) Admiral too, thus a top tier fighter.
Kuzan did try to freeze Laws sub as it fled underwater from Marineford too.
Jinbei gives the SHs such an IMMENSE advantage for the SHs in naval battles (although Egghead beginning incident was a clown fest) and thus should be a nightmare for Blackbeards DF obsessed crew, if they fight on sea ofc.