What is the underground water biome in calamity?

New tiny biome/chamber? : r/Terraria

So Is this normal for this biome? (Calamity mod) : r/Terraria

Is this normal world generation?

A bias Calamity Mod Review., Page 5

Concept art of the Calamity biome expansions: Brimstone Crags : r/Calamitymod_

Ninjabattler - Terraria Calamity Mod, Hardmode

Calamity Mod Sulphurous sea weird world gen.

Biomes - Calamity Mod Wiki

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

An Introduction to Calamity Mod

Why is my ocean biome a sulphuric sea biome simultaneously? : r/CalamityMod

Biome Blade - Calamity Mod Wiki

Calamity Mod Sulphurous sea weird world gen.