Surf ski belongs to the category of paddling craft. It is the longest type of kayak and is designed specifically for speed in the open water. The sport is commonly performed in the ocean. There are mainly two types of surf skis: namely the spec ski and the ocean ski. The spec ski is used by lifeguards and the design is strict to certain specifications for choppy and tougher maneuvers in and out of wave zones. The ocean ski is longer with a deeper cockpit to aid with long distance paddling and racing swells downwind. The length is typically between 16-21 feet and the width between 40-50 centimetres making them very fast in the water. Only the K1 and K2 kayak that feature at the Olympics is faster. The design makes them less maneuverable than the spec ski.   

Surf skis have an open cockpit with most using a self-bailer to ensure water does not get to the cockpit area, which also means it is easy to remount should a paddler capsize. The surf ski is steered by a foot-controlled pedals connected to the stern rudder. The design makes it perfect to deal with waves zones and the open ocean waters. Together with the unique designs, and the paddlers required stamina and physical training, surf ski is a popular pastime for recreational purposes or for competitions. The sport has an annual World Surf Ski Series that includes locations like USA (Oregon), Dublin, Cape Town, Hong Kong, Perth and Sydney. The series is independent from the International Canoe Federation (ICF) that oversees up the 14 disciplines, of which canoe ocean racing is specifically for surf skis. The ICF also have a series with a world ranking system.