Here Underwater Biome 1.15.1-1.14.4 is a modification that will add a unique marine biomes to your game, and with it you can get a new mobs with various random structures. The Underwater Biome will also make exploring the world more exciting with unique bosses and the ability to find special weapons and accessories!
You will find many flooded vanilla biomes, for example this phenomenon often occurs on the Amazon river. Moving on such a surface is almost impossible or very slow, you will need to adjust to build a comfortable house.
Screenshots

How to install Underwater Biome Mod
- Download and install Minecraft Forge
- Download a Mod
- Unzip it and copy to C:\Users\User_Name\AppData\ Roaming\.minecraft\mods
- Ready