A double kayak is a type of boat designed for use by two people. The kayak is long and narrow to improve speed through the water, and the paddlers propelling the boat forward will either sit inside the boat or on top of the deck of the boat, depending on the kayak's design. A double kayak is usually a bit longer than a single kayak designed for one person, and the stability of the boat will depend on the balance and coordination of the paddlers. The specific design of this type of vessel will vary according to its intended purpose.
A kayak usually features one cockpit in which the paddler will sit, but a double kayak will have two cockpits to accommodate two paddlers. Some types of kayaks, such as touring kayaks, will require the paddlers to sit inside the cockpit with their lower bodies concealed within. Other designs allow the paddlers to sit on top of the deck in a molded cockpit; these types of boats are usually used for beginner kayakers, recreational paddlers, and fishermen who want more mobility while in the boat. Kayaks that allow the paddlers to sit on top of the boat are usually a bit wider than other models for extra stability.
Maneuvering the double kayak takes a bit of coordination between the two paddlers. Touring kayaks often feature a rudder used for steering in rough waters, and is operated by a series of foot pedals positioned in the cockpit of the paddler at the rear of the boat. This paddler is therefore primarily responsible for steering the vessel, especially through rough waters. The person paddling at the bow, or front, of the boat is primarily responsible for power output to propel the boat forward. Paddlers in a double kayak may coordinate their paddle strokes for optimal power output as well as to prevent the paddles from colliding.
As is the case with other types of kayaks, the length and width of the double kayak will vary according to the intended purpose. Recreational boats are generally shorter and wider for stability, while touring kayaks tend to be longer and thinner to make higher speeds possible. Narrower kayaks tend to be less stable laterally, so the paddlers will need to be experienced enough to keep the boat balanced. Sometimes the kayaks are shorter for maneuverability rather than speed; this is common among whitewater boats.