Ocean Environs

D&D 2024 rule: Ocean Environs. Source: Ghosts of Saltmarsh. rule type Rule For those who dwell on land, the sea is an alien world filled with unpredictable hazards. Yet rare treasures hide in the depths, making such dangers well worth the risk for brave and brazen mariners. This section details a variety of environmental features one might encounter both on and beneath the waves. Blue Holes A blue hole is a circular sinkhole that forms on the bed of the sea in shallow water. The deep blue water of the hole creates a stark contrast with the lighter color of the shallow water that surrounds it. Blue holes have diameters of 1d10 × 100 feet and are 1d10 × 100 feet deep. Blue holes are filled with secrets. Many blue holes hide monsters or treasure, as shown on the Hiding in Blue Holes table. 1 2d10 sahuagin 2 1 giant octopus 3 1d4 + 1 Chuul 4 1 sea hag and 2d4 merrow 5 1 plesiosaurus 6 1d4 Swarm of Quippers 7 2d4 Reef Shark 8 1 giant shark 9 1d6 items from Magic Item Table A in chapter 7, "Treasure," of the Dungeon Master's Guide 10 Treasure rolled on the Treasure Hoard: Challenge 0-4 table in chapter 7, "Treasure," of the Dungeon Master's Guide Hiding in Blue Holes Coral Reefs Coral reefs grow all over the ocean floor, though most are found within depths of less than 150 feet near the shoreline. Reefs range from a few feet to over 1,000 miles in length and width. These colorful ecosystems house small fish, crustaceans, and mollusks. As a result, predators come to reefs looking for prey. Uneven and sharp, coral reefs can harm those forced into them. A creature forcibly moved on the reef-without using the creature's action, bonus action, or reaction-takes 3 (1d6) slashing damage per 5 feet of reef that it is pushed over. Currents Ocean water is moved by wind and tides to create constant river-like flows called currents. Tidal currents are typically the strongest. They're usually found within 50 miles of shore and at depths of less than 300 feet. These currents have a s...