Floating jetty, dam access

[Kanezza]

Hi, Has anyone successfully and cheaply made a floating walkway into their dam. There are plenty of >$600 options on the web but I'm thinking of a large painter's plank with one end fixed by chains/ropes that can be let out or pulled in and the other floating on plastic drum(s) (which I haven't found yet) and the whole thing stable enough to walk along and hop into a dingy from or bucket some water out or put the suction hose into the dam from. A mate says he has seen something like it in QLD (where they're not dams but tanks) using what must be empty fertiliser drums or something.
Thanks, Phil A