The great ocean.

I had a idea about a new ocean biome. The idea would be like if you go far enough in the ocean you will come across the great ocean it could be like the deepest ocean but inside the deep ocean there could be a mini boss or some other kind of mob that is guarding a bigger shipwreck that has better loot than the normal shipwreck. There could even be things like anglerfish in the deep ocean and you can rarely fish them up and they could glow in your hand and put them in a bucket. This is just a random idea I had.