I have 15 of these, and I'm sure there is something useful I they can be turned into. My first thought was some type of rod storage, or lure storage with some cut 2-liter bottles. What can you think of? Sorry the pic is sort of huge.
I would cut them here so they are flush next to eachother, except the end pieces, and stack them in a row of 8 and attach to plywood (do this twice). Then put the plywood up against the wall and there you have it. 24 rod holder. View attachment 119145
I think they are too big to make rod holders, but it may work.
A couple of ideas:
Cut a piece of plywood to fit and secure to the bottom of one of them. Turn it upside down and stack to make variable height trailer stands or even step stools. They hold a lot of weight but are light.
You can make a deposit bottle return........ a small grocery/beverage store........... They do hold allot of weight...... do you need to store a trailer with the wheels off the ground?
OH wait..... I see you are in Florida........ make a Hoveround racing course