A definite plus is that is totally fuel-free (ther than getting yourself and a kayak to the 10th street boat launch on the Everett waterfront). The kiteboarders carry their gear in backpacks on kayaks from the boat launch over to Jetty Island.
The west side of Jetty Island is a great place for that sport since it has fairly steady winds and shallow water that is warmer than the rest of Puget Sound (although not so warm that they aren't wearing wetsuits or drysuits). When they fall they are often in water that is shallow enough to stand up in.
I've been reading about kiteboarding and learned the first step is to learn to fly a Beginner Kite which costs about 100 dollars. Knowing how to fly the kite will make kiteboarding lessons much more productive. If it looks like a sport that would appeal to you Seattle Kiteboarding at 17230 Bothell Way NE, Seattle WA. has equipment and kiteboarding lessons.