Storing on the water?

I grew up sailing a sunfish during summers off a beach on Lake Michigan. Many years later and recently retired, I'm thinking it's time to get back into a sailboat. I now live on a "tidal river" in Massachusetts, with a small floating dock, which floats in water half the time and sits on sand half the time, depending on the tides. We have a Boston Whaler we keep tied to the dock that simply beaches itself when the tide is low, and a couple of Hobie kayaks we pull out and store on top of...

Storing on the water?