Sea Cave

Caves cut into sea cliffs by the waves, open at low tide and drowned at high tide. Inside, the light is green and wavering, every wave booms like a drum, and the air smells of salt, rotting weed and the droppings of the birds on the ledges. Anemones, mussels and starfish cling to the walls, seals haul out on the shingle at the back, and pigeons and shags nest in the roof. Smugglers, hermits and wreckers have all used them, and fishermen shelter in them from a squall. The sea comes back faster than one thinks, a swell can fill a passage to the roof without warning, and some caves blow spray from holes far up the cliff. Fingal’s Cave, on the Scottish island of Staffa, with its columns of black basalt, is a cave of this kind.

Hear it

• By day: Sea Cave (In the album RPG Ambiences Vol. 2)
• In a storm: Booming Waves Cave (In the album RPG Ambiences Vol. 9)
• At camp: Sea Cave Campfire (In the album RPG Ambiences Vol. 2)

Adventure hooks

1. Smugglers use a sea cave that can only be reached at low tide, and the excise officers want it watched. The smugglers are the officers’ cousins, and everyone at the wedding next week will be both.
2. A boy climbed into a sea cave after birds’ eggs and was caught by the tide. He is alive in an air pocket, shouting, and the water has not stopped rising.
3. At certain tides a sea cave sings a low note that carries for miles, and the fishermen steer home by it in fog. This year it has gone silent, and the first boat has already struck the rocks.
4. A hermit monk once lived in a sea cave, and pilgrims still come to touch his stone bed. Someone has carved a new message on the wall in his hand, telling the pilgrims to go home and mind their own sins.

Creatures

• Giant Crab (a threat to the unwary, Challenge 1/8)
• Giant Bat (a threat to the unwary, Challenge 1/4)
• Swarm of Bats (a threat to the unwary, Challenge 1/4)
• Giant Octopus (a fight to fear, Challenge 1)
• Pirate (a fight to fear, Challenge 1-6)
• Bronze Dragon (a fight to fear, Challenge 2-22)
• Merrow (a fight to fear, Challenge 2)
• Sea Hag (a fight to fear, Challenge 2)

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 fish

Rock Crab, Glowspine Eel, Reef Octopus, Sightless Crab, Abyssal Angler

Nearby biomes

Cave, Mine, Underground Water

Open it in Biomes — MGS Toolbox