There is always a bigger fish.

(Mosasaurus)

Be careful if you have a tamed megalodon or two following your raft. Wild megas will agro your tamed ones and once one dies (tamed or wild) they start to swarm which means yours are as good as dead.

Go to Red obelisk you'll thank me later

Avoid this animal in the wild as it is aggressive. But once tamed they make a good water defense for underwater or island bases, both pvp and pve

Don't get stuck.