The best self rescue is a good eskimo roll. With a spray skirt and paddling jacket you are upright in a dry boat in less than 2 seconds using much less effort to climb into a kayak and you are dry. In windy conditions you will be hard presed to controll your swamped kayak If you manage to get back in. You must consider hypothermia. Lets start with the 50/50 rule. If you are in 50 degree water for 50 minuts, and they get you imediately to the hospital you will have a 50% chance of surviving (this assumes that you are wearing street clothes). That said, always dress for imersion. This will greatly slow down the rate of body core heat loss. Take a rolling class any one with legs down to the knees can do it. If not take a basic kayaking class. This will teach you several important strokes and some partnered rescues. Then always paddle with a partner. There are some self rescues like the paddle float rescue, but in rough conditions this may take several tries and take a lot of energy. Also you can split the seams of a kayak if it is swamped and beach lands in a dumping wave.

Kayak safely.

Sage

P.S. On flat water a hand held bilge pump ($30) will work fine. For solo paddling in rougher conditions you will need both hands on your paddle. A foot builge pump system can be set up for about $75 and a electric for less than $100.