It's the slowest underwater tame in the game, with every wild creature being able to catch up to it (and kill your tame) except cnidaria (50% slower), basilos (16% slower but why would you get rage debuff with it), anglerfish (literally 4% slower so they'll probably still catch up to you given that you're riding on it with some of its weight taken up), and all small fish except piranhas.

But with the amount of stamina it has, every underwater tame still could catch up to you.