Deep Ocean
Overworld (water)
The regular ocean dropped to twice its depth - seafloor around Y=30, almost no islands, and the home of ocean monuments with their guardians and elder guardians.

Resources
- Ocean monument loot: sponges, gold blocks, prismarine, sea lanterns
- Tall seagrass (more common than in shallow oceans)
- Cod and salmon schools; dolphins for speed boosts
- Kelp along the gravel floor
Mobs
- Guardians and elder guardians around the monument
- Cod, squid, glow squid, dolphins and nautiluses
- Drowned - trident throwers can spawn riding a zombie nautilus
Structures
- Ocean monuments (only in deep ocean variants)
- Shipwrecks and ocean ruins
- Cannot border land - except mushroom fields
Why go
- The only place to find ocean monuments and sponges
- Guardian farms: infinite prismarine and sea lanterns
Tips
- Drink water breathing and bring night vision before raiding a monument: mining fatigue III from elder guardians blocks breaking blocks for 5 minutes.
- Kill or milk-bucket the three elder guardians first to clear mining fatigue, then farm sponges in the wet sponge rooms.
- The seafloor sits near Y=30 - a conduit makes building an underwater base here far easier.