Sulphurous Sea

The Sulphurous Sea, also known as the Sulphur Sea, is a biome added by the Calamity Mod which spawns upon world creation. It replaces the Ocean on the Dungeon side, and is located on top of the Abyss. Its water is turquoise colored, and it contains a hole leading to the Abyss.

It is primarily composed of Sulphurous Sand that makes up multiple islands that generate at sea level, where Acidwood Trees will grow when not covered by water. A series of caves composed of Sulphurous Sandstone and Hardened Sulphurous Sandstone will generate between the surface of the Beach and the Abyss, where Rusty Chests can be found. Coral, Seashells and Starfish also grow faster in this biome, and many new decorative objects such as Corroded Fossils and Pillars will generate in the Sulphuric Caves.

Dangerous Sulphuric Bubbles can generate above any Sulphuric Sand or Sandstone when they are covered by water. These bubbles can't hurt the player until they have reached their maximum size. They deal 20 damage and inflict Venom for 2 seconds. The water is also hazardous, inflicting Sulphuric Poisoning that grows more damaging the longer the player stays in it. Steam Geysers also generate on the Beach, and will fire steam at the player if they walk over them.

Acid Rain can start in this biome at any time after the Eye of Cthulhu has been defeated. Acid Rain will cause numerous new enemies to spawn throughout the game at multiple points of progression, many of which have new drops.

The Aquatic Scourge boss can spawn here naturally (but very rarely) or can be summoned here by using Seafood, and The Old Duke can be summoned here by using Bloodworms as bait when fishing.

Fishing
When fishing in the Sulphurous Sea the player can catch Abyss related items, these depend on the player's fishing power, and are as follows:
 * Abyssal Crate - Can be caught with any fishing power.
 * Planty Mush - Can only be caught with 0 to 80 fishing power.
 * Planty Mush's coded requirement is actually 40 to 80. However, as this item replaces Junk catches in the Abyss, it is technically 0 to 80.
 * Alluring Bait - Can only be caught with 40 to 159 fishing power.
 * Abyssal Amulet - Can only be caught with 110 to 239 fishing power.

Tips

 * This area is very dangerous for early game players, as it houses several fast high-damage enemies, like the Trasher, and the area's poisonous water will quickly drain an unprepared player's health.

Trivia

 * The theme heard while in the Sulphurous Sea is wasteland, which was composed by the artist DM DOKURO.
 * If the Calamity Music add-on mod is disabled, the Desert's theme will play instead.
 * The turquoise coloration of the water is representative of real life volcanic sulphuric lakes.
 * The enemies found within the Sulphurous Sea are immune to almost all debuffs, possibly referencing their adaptation to the toxic environment.
 * Due to the urine-like coloration of the biome's water in previous versions of the mod, this biome has been known by the community as the "piss sea/ocean".