The design allows lateral resistance upwind, without the need for a skeg, daggerboard or centreboard. The skeg also acts as a rudder when the engine is not running. His later designs were generally performance oriented fin and skeg or fin keel designs. To counter this, they use a rudder or skeg. It has a heavy bronze keel and skeg, watertight compartments, and self-bailing features. The centreboard together with the skeg give the boats their directinal stability. This somewhat beard-like sternward extension of the keel is the basic skeg. A skeg, was added to the second step on the Kawanishi H8K flying boat hull. A fixed fin, known as a skeg, has been used for directional stability. Both a skeg and ""rail" "fins"" stabilize the motion of the surfboard. This link explains the subtleties of the kayak skeg. It is analogous to a skeg on boats and ships. In that sense, the skeg acts as a lifting foil. Its purpose and use are rather different from those of the surfing skeg. The board was without a skeg, which had yet to be invented.