A skeg is a sternward extension of the keel of boats and ships which have a rudder mounted on the center line. It is also the lowest point on an outboard motor or the outdrive of an inboard/outboard. The term "skeg" also applies to the blades that extend from the hull of a kayak to provide stability and decrease drift in choppy waters and challenging conditions. The following are some key points about skegs:

• A skeg is employed in the type of kayak used on more open water such as the sea. Its purpose and use are rather different from those of the surfing skeg.
• Skegs are usually retractable blades, or “fins” that extend from the hull of a kayak — usually at the stern, or rear of the boat.
• The most important reason for a skeg in a vessel is the hydrodynamics. The design of the skeg dramatically influences the flow patterns, and this, in turn, affects the dynamics related to the rudder and the propeller(s). This improved flow pattern reduces drag and resistance. Moreover, the propeller efficiency also increases.
• Skegs have been found to be useful in yaw control and reducing sway motions as well. Furthermore, skegs also play an important role in seakeeping by improvising stability and vertical balance characteristics like increasing.
• Skegs are shaped like a fin or rudder because it acts as such when the boat is in motion. When a skeg is in good working order, it keeps the boat running on a straight and even path. When you need to turn the boat, it makes the maneuver smooth and easy.

In summary, a skeg is an important component of boats and kayaks that helps with stability, directional control, and hydrodynamics.