What is the underground water biome in calamity?

Arsenal Labs - Calamity Mod Wiki

Steam Workshop::Oceanic world caves Reworked

Ocean randomly turned sulfuric, is this fixable? : r/Calamitymod_

I can't find my Sunken Sea biome, any help would be greatly appreciated. I wonder if it didn't spawn because my one underground desert goes all the way to hell. : r/CalamityMod

the abyss is just an underground biome and the non-sulphurous ocean is still a sulphurous sea biome. the abyss enemies do not spawn and the items are too easy to obtain, but

2023 Calamity biomes and never

Biome Blade - Calamity Mod Wiki

Vernal Pass - Official Calamity Mod Wiki

Biome Blade - Official Calamity Mod Wiki

Terraria Calamity Mod 1.4: Exploring, Collecting Resources, and Upgrading Armor — Eightify

Not a suggestion. I just really wish ocean biomes n sea caves had an update to include an underground ocean reef using the new coral blocks and shell piles in these areas

Desert Scourge + Sunken Sea biome Calamity Death Mode Rogue Class Let's Play, Episode #3