don't bother, Boss; trust me, done did and didn't last. You need cork bark, like Dime has shown. It'll last a lot longer. The maple stuff will soak up water and then it'll lie low in the water. Any turtle (or other creature) climbing up will lower it even more. And I bet I didn't get a season out of it. C O R K B A R K. That's what you use.
Btw, Dime, that's a good load of bark; think it cost me like $25-$35 for that much. More expensive than I'd have thought but I ordered from a reptile supply place, so maybe that's the markup. When I was looking, it wasn't the holiday season; I may have to go visting a craft store this week and stock up. I used to have smaller (not large enough for turtles basking, esp 4 of them) pieces for orchids. Cobbled up some together and put them on a styrofoam base. That was MY cork floaty v1. This last is ONE piece, approx 12" by 20", so enough for turtle growth in the future.