Vaaccess, Aquaponics on a floating island like you suggested would be pretty cool! Aquaponics has really exploded the last few years in popularity, but, it is still very expensive to get all the equipment, and room, to grow fish and vegetables! Unless you are very handy, have a lot of things like tanks, PVC pipes, pumps, and everything else needed, you can spend some big bucks on pre-fabbed items to grow a hundred dollars worth of veggies that grow in really wet environments and another couple hundred worth of fish.
I used to plant about a one acre size garden on my old place. My mom asked me, "Why bother?"...My answer, "I like paying 10 times the price for my fresh veggies".
