A floating pond island always struck me as a convenient way to make use of old tires, by bolting them together you can make them any configuration you like and after covering them with something suitable as structure for plants to mesh together on, are going to be doing something useful long after they were considered junk...
Creating shade from hot midday sun, protection from predators, a place for fish to spawn, and the bare rooted plants are going to be filtering water quality at the maximum rate...
Regards, andy
