Deep Sea

The dark, cold, crushing depths below the reach of sunlight. There is no sound but the creak of whatever comes down from above, and the only light is the cold glow some creatures make for themselves. Anglerfish, gulper eels, giant squid and pale crabs live there, slow and patient, and eat what sinks from the sunlit sea. No one goes down there: fishermen only lower lines and nets into it and haul up its strangers, and sailors tell of what they saw rise from it. What comes up is rarely forgotten, and the depths are said to keep every drowned ship and sailor of the world. The Mariana Trench, the deepest place in the oceans, is deep sea of this kind.

Hear it

• Under the water: Underwater (In the album RPG Ambiences Vol. 2)
• Diving: Diver (On Patreon, Guardian tier)

Adventure hooks

1. A longline came up from the deep with every hook bitten clean through. The last hook held a tooth as long as a forearm, and a scholar ashore will pay for the rest of the animal.
2. A diver in a bell went down further than anyone ever has, and came up talking about lights that move in patterns. He is drawing the patterns on the tavern walls, and each night they are different.
3. The trench off a fishing village is said to hold the drowned of the whole coast, and once a year the village lowers a lantern into it on a long chain. This year the chain came up shorter than it went down.
4. A deep fish hauled up in a net has swollen into the ugliest thing the market has ever seen. The fishwife who owns it charges a coin a look, and the bishop wants it burned as a demon before the queue gets any longer.

Animals

• Sperm Whale (can wound or kill, in families, day and night)

Creatures

• Sahuagin (a threat to the unwary, Challenge 1/2)
• Aboleth (deadly, Challenge 10)
• Storm Giant (a fight to fear, Challenge 13)
• Dragon Turtle (deadly, Challenge 17)
• Kraken (deadly, Challenge 23)

This work includes material from the System Reference Document 5.2.1 ("SRD 5.2.1") by Wizards of the Coast LLC, available at https://www.dndbeyond.com/srd. The SRD 5.2.1 is licensed under the Creative Commons Attribution 4.0 International License, available at https://creativecommons.org/licenses/by/4.0/legalcode.

To gather

Sperm Whale Blubber, Sperm Whale Spermaceti, Sperm Whale Tooth

To fish

Cod, Glowspine Eel, Lanternfish Swarm, Sightless Crab, Sunken Cargo Crate, Thermal Vent Worm, Chambered Nautilus, Giant Squid, Abyssal Angler, Sea Serpent Hatchling, Leviathan Barnacle

Nearby biomes

Coastal Shelf, Coral Reef, Kelp Forest, Open Ocean

Open it in Biomes — MGS Toolbox