You could make a floating dock with plastic 55 gallon drums and frame it with 2x6's. For the decking you coud use pressure treated deckboards. I'm in the works of makeing one myself. The size I am building is 8'x16'. Put a stainless steel ladder off to one side. I can tie the paddle boat off from the other side. The wife wants one to layout on and absorb sun, I want it to fish off from and when we jump in you never have to touch the bottom. I am going to use ratchet straps to hold the plastic barrels in place. I figure I'll pull it out of the water with my 4x4 4 wheeler for the winter and when I go to put it back in the spring I'll pressure wash and stain it with some Thompsons water seaal or something I'm going to anchor mine to land with cable and rebar and just make some kind of steps/ramp to get onto it from land. By the way, you crazzy jumping in the pond already? \:D