Subaquatic is a mod that adds lots of ocean-related content, and fixes some bugs!
Dependencies: Fluidlogged API (required) and AssetMover (required on client)

Bug Fixes (as of this mod's latest version):
-MC-1691 (Sprinting/falling on thin/small blocks uses the block below for the particles)
-MC-8820 (Walking on thin/small blocks produces sounds from the blocks below them)
-MC-118096 (Incorrect position of particles when using bone meal on grass block)
-MC-129794 (Water particles are not biome-affected)
-MC-130137 (Grass and mycelium don't decay underwater)

Big Features (as of this mod's latest version):
-All ocean biomes from Update Aquatic!
-Bubble columns (works in ANY Material.WATER fluid!)
-Chest boats, ender chest boats, ender chest minecarts, crafting table boats, crafting table minecarts, and furnace boats!
-"Fish", cod, salmon, pufferfish, tropical fish entities!
-Glow lichen
-Hanging roots & rooted dirt (generates instead of dirt under all properly coded trees)
-Kelp, seagrass, sea pickles, and coral generation!
-Mud and mud bricks
-New villager type: Marine Biologist (see source code for trades)
-Froglights (currently only obtainable through marine biologist trades)
-Realistic fishing (fishing reels in actual fish entities instead of fish items! note that this mod also adds an enchantment that counteracts this)
-Serves a library mod for other mods to add their own custom ocean biomes!
-Smooth blocks (smooth stone, smooth sandstone, smooth red sandstone, smooth quartz, and smooth lapis lazuli)

Small Features (as of this mod's latest version):
-Baby zombies burn in daylight
-Bubble pop particle and sound
-Bubble particles last longer
-Bubble particles appear when chests are opened underwater, and appear during underwater explosions
-C418 underwater ambient sounds and music
-Cauldrons apply water physics to entities
-Configurable biome blend radius size
-Configurable biome water surface and fog colors
-Faceless pumpkins from 1.13 (can be carved using shears)
-Fish buckets (works with any Material.WATER bucket)
-Gradual air replenishing mechanic from 1.13
-Items and xp orbs float on water
-Levers emit redstone dust particles while powered
-Pumpkins can be placed without a block below
-Toggleable enchantment glints for potions, xp bottles, and dragon's breath
-Translucent water bottles
-Translucent xp orbs
-Water particles (splashes, bubbles, etc) apply water biome colors, and respect modded fluid colors
-Vanilla's mushroom blocks, stems, and hyphae are craftable and silk touch-able
-Vanilla water buckets now use the forge bucket renderer to be consistent with modded buckets

Planned Features (in order of priority):
-More of the wild update's mangrove swamp content (frogs, tadpoles, etc)
-Dolphins
-Drowned
-Tridents
-Turtles
-Shipwrecks
-Buried treasure
-Conduits
-Phantoms

Using this mod alongside Aqua Acrobatics is highly recommended for the best experience!
This mod was originally made for the 1.12.2 Ocean Modjam hosted by the 1.12.2 Modding Coalition