The naturally sheltered, deepwater basin that made the city such a good location for an imperial seat of power is a bustling place. Its chill waters are kept fairly clean by the diligent work of the Guild of Watermen and the merfolk of Tharqualnaar. The City Guard’s harbor patrol controls access to the harbor above the waves, using retractable chain-nets and the walls of the defensible harbor to bar entrance or exit by particular ships.

Deepwater Harbor is divided into two smaller harbors— the Great Harbor, through which commerce and transportation flows, and the Naval Harbor, restricted for the use of the navy.

Two major islands, Stormhaven and Deepwater, enclose the harbor. Notable landmarks include Boatscrape Cove, where ships are beached to be cleaned of barnacles and worse; Deepwater Beach, where mermaids often come to sun and flirt with the guards; and the Sea Stacks, sharp rocks that deter the close approach of sailing ships.

Throneport’s sewers empty into the harbor at places covered with extremely large and strong gratings, regularly patrolled by bands of merfolk. The merfolk use catch-nets on poles to scoop and gather the debris into large tow-globes for transport far out into the Sound. The harbor’s rocky, sloping bottom is thinly covered with mud, especially at the southern end of the harbor. It is kept free of plants and litter by the merfolk, which makes for remarkable underwater visibility.

UNDERWATER RESIDENTS

The Great Harbor is home to a merfolk village named Tharqualnaar. The first merfolk residents arrived only a few hundred years ago, refugees from sahaguin attack. When the King of Galifar offered his protection and a place in the city, they accepted and have lived in Deepwater Harbor ever since.

All adult merfolk of Tharqualnaar are considered members of the City Guard if they contribute to the defense of Waterdeep, though their weaponry and equipment is their own. The city pays a stipend of food, medical supplies, and trade-bars to all who loyally patrol the harbor depths against invaders, predators, and shipping hazards. The merfolk are expected to aid in the recovery of corpses, spilled cargo, sunken vessels, and the like. They are free to travel outside the harbor, but rarely patrol more than a quarter-mile from the western shore of Deepwater Isle or a half-mile north of Stormhaven Island.

There is a brisk underwater trade between Tharqualnaar and the aquatic residents of Estaby. Traveling locathah merchants and nomadic lizardfolk tribes also make for regular trade under the waves. Sahaguin, though, are hunted and killed on sight, with the City Guard rendering assistance when necessary.

DEEPWATER BEACON

This underwater lighthouse stands at the edge of a deep depression in the harbor’s floor, lit by a magical light which guides the merfolk patrols and keeps the sea wraiths confined within the caverns below. The lighthouse serves the merfolk as a tethering spot for giant seahorse steeds, as an armory, and as a storage facility. It also serves ships above by acting as a subsurface beacon.