When sailing alone, or out with a group in more than 3' waves, we use 9' surfboard leashes. The "board" end has large heavy duty velcro, doubled up that comfortably mounts to the rear aka support. They came with soda can koozie that holds the coil of "line". I keep the ankle end, velcroed to my seat strap when not in use. I can now, one handed, remove it from the seat at my side. pull enough to reach my ankle in full stroke of the pedal drive, and attach. I then can work out any twists in the "line" as there are swivels at both ends. If I ever fall out, the rest of the line feeds out of the koozie (the line goes through the koozie so it's not lost).
I have used it when changing rudder pins and at 9' is perfect to keep you 2' behind the rudder to work on it.
I feel more comfortable on my ability to self rescue with it on, either when out by myself, or in a group.
We added these to each AI after a friend jumped in for a swim in light winds (with the sail rolled up) and could NOT catch the AI to get back in. He is a very good swimmer. I had to stop his boats movement with mine for him to catch it.
You can barely make it out on the right side of the picture below. See the 1 1/2" strap on the aka support and what looks like another 1 1/2" strap around one of the seat straps.
Kayaking Bob