Sealed-hull craft were developed for leisure use. Sit-on-top kayaks come in 1-4 paddler configurations. Sit-on-top kayaks are particularly popular for fishing and scuba diving, since participants need to easily enter and exit the water, change seating positions, and access hatches and storage wells. Ordinarily the seat of a sit-on-top is slightly above water level, so the center of gravity for the paddler is higher than in a traditional kayak. To compensate for the higher center of gravity, sit-on-tops are often wider and slower than a traditional kayak of the same length.