A sea kayak or touring kayak is a kayak developed for paddling on open waters of lakes, bays, and the ocean. Sea kayaks areseaworthy small boats with a covered deck and the ability to incorporate a spray deck. They trade off the maneuverability of whitewater kayaks for higher cruising speed, cargo capacity, ease of straight-line paddling, and comfort for long journeys.

Sea kayaks are used around the world for marine (sea) journeys from a few hours to many weeks, as they can accommodate one to three paddlers together with room for camping gear, food, water, and other supplies. A sea kayak usually ranges anywhere from 10–18 feet (3–5½ meters) for solo craft, and up to 26 feet (8 meters) for tandem craft.