Coastal Shelf

Coastal Shelf
Karim saari, CC BY 4.0, Wikimedia Commons

The shallow sea over the edge of a continent, green or grey rather than blue, where most fishing boats work. Its swell is short and choppy, its fogs come in without warning, and on deck everything smells of brine, tar and fish. Cod, herring, mackerel and flatfish crowd its banks, seals and porpoises follow them, and gulls follow the boats. Fishermen, traders and navies cross it every day, and its sandbanks, wrecks and lightships are known by name along the coast. People fear the sudden gale, the fog on the banks, and the shallows that break a keel far from any land in sight. The North Sea, shallow and stormy over its sandy banks, is a sea of this kind.

Hear it

For the table

Ground
At sea: Sailing ship: 77 km a day, Warship: 96 km a day, Galley: 154 km a day, Longship: 115 km a day
Water
by season
Foraging
rich

Hazards

  • Storm at sea. The wind rises for hours, the sea builds into grey hills and the crew reefs the sails or runs before it. No one sleeps dry; the ship goes where the storm sends it, not where the chart says.
  • Rain squall. A black wall of rain walks across the water and swallows the ship. For an hour the bow cannot be seen from the stern.
  • Sea fog. A white fog lies on the water. Bells and shouts carry strangely, another ship can loom up a cable away, and the coast is wherever the lead line says it is.
  • Reefs and shoals. Rock or coral a fathom under the surface, a sandbank that moved since the chart was drawn. A ship that strikes may float off at the next tide, or open her hull.
  • Becalmed. Not a breath of wind. The sails hang, the sea turns to oil, the sun beats on the deck and the water casks go down while the ship goes nowhere.
  • Man overboard. A green sea sweeps the deck, or a foot slips at the rail, and someone is in the water. By the time the ship comes about, the swimmer is a dot among the waves.
  • Fall from the rigging. Aloft in a blow, a frozen hand lets go of a wet line. Falling onto the deck breaks bones; falling into the sea is luckier, if someone sees it.
  • Seasickness. Landsmen turn green the first days out, or when the sea gets up. Most find their sea legs in two or three days; a few never do.
  • Frigid water. In cold seas a fall overboard is a race against the cold. The swimmer loses the use of hands, then of legs, long before drowning.

D&D 5e

Plays as
waterborne, by the ship pace at most
Checks
forage: Survival DC 15 · find the way: DC 10 · search: DC 15
Creatures are spotted at
6d6 × 10 ft
  • Storm at sea. Strong wind gives Disadvantage on ranged weapon attacks, puts out open flames and scatters fog; a flyer must land at the end of its turn or fall. A ship sailing into a strong wind moves at half speed.
  • Rain squall. Heavy rain makes everything in it Lightly Obscured, gives Disadvantage on all Wisdom (Perception) checks and puts out open flames.
  • Sea fog. Heavy fog is Heavily Obscured: a creature trying to see something in it has the Blinded condition. Patchy fog is Lightly Obscured: Disadvantage on Wisdom (Perception) checks that rely on sight.
  • Reefs and shoals. (House rule) House rule: the lookout makes a Wisdom (Perception) check, DC 15 by day, 20 at night or in rain. On a failure the ship strikes: it takes 4d10 Bludgeoning damage (reduced by its damage threshold as usual) and stops until the crew warps it off, about an hour of work per 10 damage taken.
  • Becalmed. In a dead calm a ship cannot move under sail: it must be rowed, or it lies still. A ship that cannot be rowed makes no way that day.
  • Man overboard. Swimming costs 1 extra foot of movement for each foot moved (none with a Swim Speed). In rough water the GM may ask a DC 15 Strength (Athletics) check to move at all.
  • Fall from the rigging. A fall deals 1d6 Bludgeoning damage per 3 m (10 ft), at most 20d6, and leaves the creature Prone unless it took no damage. Falling into water, it can use its Reaction for a DC 15 Strength (Athletics) or Dexterity (Acrobatics) check to enter head or feet first and halve the damage.
  • Seasickness. (House rule) House rule: a creature new to the sea makes a DC 10 Constitution save at the start of each of its first three days aboard, and on any storm day. On a failure it has the Poisoned condition until the next dawn. A success on two days in a row ends the risk for the voyage, except in storms.
  • Frigid water. A creature can stay in frigid water for as many minutes as its Constitution score. Each minute after that, it makes a DC 10 Constitution save or gains 1 Exhaustion level. Cold resistance or immunity, or being adapted to icy water, passes automatically.

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.

Adventure hooks

  1. Fishermen have dragged up the upper half of a bronze statue in their net. Two scholars are bidding for it, and a third stranger offers more than both to have it dropped back exactly where it was found.
  2. The herring have left the old banks, and the fleets of two harbours are crowding onto the last good ground. A skipper wants a crew bold enough to fish in the other harbour’s waters, and a few fists.
  3. Fog has come down over the banks and the boats ring their bells to find each other. One of the bells answering belongs to a boat lost with all hands last winter.
  4. A fisherman found a gold ring in a cod and became the richest man in the harbour. Now every crew guts its cod at sea, and someone ashore is quietly selling rings to slip inside them.

Animals

Creatures

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

Bearded Seal Blubber, Bearded Seal Hide, Bearded Seal Meat, Humpback Whale Blubber, Humpback Whale Meat, Killer Whale Blubber, Killer Whale Meat, Narwhal Blubber, Narwhal Sinew, Narwhal Skin, Northern Gannet Oil, Northern Gannet Feathers, Northern Gannet Chick, Polar Bear Fat, Killer Whale Tympani, Narwhal Tusk, Polar Bear Hide, Sea Otter Pelt, Snake Venom, Concentrated Venom

To fish

Cod, Fouled Anchor, Glacier Krill Swarm, Herring Shoal, Kelp Bundle, Oyster Clutch, Rock Crab, Wreck Timber Bundle, Coral Branch, Message Bottle, Reef Octopus, Spiny Lobster, Sunken Cargo Crate, Pearl Oyster, Reef Shark, Sea Turtle

Nearby biomes

Coral Reef, Kelp Forest, Open Ocean, Deep Sea

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