Water caves update

There are caves that are completely isolated and filled with water, right now there are only squid but I think these could be so much more, there could be a new dangerous mob based off a leviathan or underwater dinosaur that makes a chilling sound, and maybe a few prehistoric or deep ocean creatures and underwater plants, and maybe there could be some way to obtain this horrifying creatures scales, perhaps they could upgrade netherite armour, or something else. Imagine your mining and you break a block and water flows out from a blocked off underwater cave, and you see a whole new world, and hear a chilling call from the monster