Minecraft underwater world/mod neededpool

Hello everybody,
im playing Minecraft a long time and even have some small mods, but since a time i try to make a special "fun" server underwater, but didnt get it to work.

Basic Idea:
A small server with new underwater biomes, where you ONLY live underwater. You breath water and suffocate outside.


Mods needed:
- Underwater Biomes
- Setting, where 90% are underwater biomes?
- maybe other recipes to "survive" underwater (tools etc)
- breath water, suffocate on air


Is there anything like that or maybe some moddders would work on something like that?

Basic Thoughts:
- Recipes changer to make "tools" from "unterwater" materials should be "easy" (they exist as far as i know)
- Theres an "atlantis" mod https://www.curseforge.com/minecraft/mc-mods/atlantis, it create an underwater biome, where you get permanent underwater breath, haste (for underwater) and night vision. Maybe this mod and a spawnpoint wwith only that "Portal"?
But there is no information, which "Version_" it uses (only "Forge" but not the Version)

I tried something like that but with no success.

So, please, if there ARE such mods, can you show me?
Ideal were Fabric 1.16.2 but i guess thats only possible for Forge 1.12.

So PLEASE help me ;)


Thanks


...DX