A rudder blade deflects water in a particular direction, causing the boat to turn; a skeg creates resistance to the turning affect caused by the wind and causes the boat to go straight. In both cases, the devices are being used to make a boat track straight when the wind is trying to make the boat turn.
Why use a skeg on a kayak?
Skegs are used only to assist in the tracking of a kayak.
In cross winds and following waves, you can deploy a skeg to help your kayak track straight. When the skeg is no longer needed, it can be raised back up inside the boat and has no effect on the performance of the kayak.
Do you need a fin on a kayak?
Inflatable kayaks: Do you Need a Skeg (Tracking Fin)? Short answer: Yes. It’s easier to go straight while paddling as hard as you like, and most except the very cheapest single-skin vinyl IKs come with one; some flat-floored models have up to three (imo, a gimmick) and many skegs are unnecessarily tall (deep).
How important is a rudder on a kayak?
A rudder gives you the ability to ‘crab’ to the wind, meaning that you turn the rudder to counter the winds push on the kayak. This allows you to paddle with normal strokes versus multiple strokes on one side of the kayak to correct for the wind thereby allowing you to maintain your momentum, making you more efficient.
How do I make my kayak track straight?
Deploy the skeg or rudder when winds are pushing the kayak from the rear. Tail winds push the kayak around, making it hard to track and stay in a straight line. Push the rudder slightly to the opposite side the kayak is being blown. Use slight paddle strokes opposite the rudder to maintain an even track on the water.