It works. I do it myself. The best thing you can do is do a quick google search on "hydroponic floating rafts" and look through the images to get ideas on what you want. If money isn't a problem, look at Biohaven floating islands, but I believe most people could make it a weekend DIY project. Building what amounts to a floating dock would work, but is probably overkill. Last year I floated those pink 4x8 sheets of foam you can pick up at a box store. Easy to make any shape you want. Cut some holes that allow you to hold aquaponic baskets or even garden center nursery pots depending on the size of plants you need. You could frame them with treated lumber to make sturdier if you want. There's a lot of plant options. I just used some ornamental grasses because I'm trying to reduce the nutrient load coming into my pond.

This year I am going to float some tires and experiment with a few vegetables (broccoli, cabbage, lettuce, peppers) just to see what happens. I've added buoyancy to the tire with plastic bottles and cut holes around the edge so that annual flowers can encircle the veggies and look better. These are going to double as location markers for a couple sunken habitat structures I have too.

Hope that helps. Wish I had a few pics. I'll do better with that this year.

J Waters
Dam'd Waters Farm
2/3 ac dam'd stream pond
BG, HBG, RES, LMB, YP