Do you mean the Hobie Cat? If so, as the pp mentioned, it can't be reserved early. But someone does need to have sailing experience.
We rented it a couple of times and both times we waited until early afternoon and they was no wait. Once we rented it, there was no one out and when we got closer to the ship, we looked back and there were quite a few out but they were mostly near the beach...most of them didn't go further out, so we had a lot of room going back and forth at the farthest point. The area you are permitted to go is not very big...I would say you can circle the whole area about 10 times if the wind was cooperating.