BenignVanilla wrote:

OK, more seriously. I am guessing the easy part is the decking. The hard
part is the buoncy...the boin...the boya...making it float. How do you do
that cheaply? I'd then think materials are the next concern. I'd probably
use Trex (that new recycled decking) so you don't have pressure treated wood
in contact with your water. If it is half as naughty as they say it is, it
must be very naughty. What then for underneath? PVC? Galvinized steel?

Plastic barrels. If they are 55 gallon drums, they will support about
440# each. You'd want them no more than half under water to keep the
deck skirting dry (fights rot and reduces leaching of treatment
chemicals), so 4 of them would support 880# out of water, 6 would
support 1320#.

Environmental rules have changed several times since I last checked,
but there is at least one type treated wood usable for decking. Might
make a difference if the wood is going to be used under water. I would
not bet on the rules staying the same for any length of time, so
better to keep the wood dry.