I made mine from the larger dia. foam floats from Wal-Mart.
Had some window screen frame in the garage, cut 2 pieces from the frame to use as cross members, made them 3 inched wider than the skids.
Epoxied the cross members into the foam floats just above the centerline of the floats to give stability in the water. Cut the floats long enough to support the weight of the heli with extra to spare.. Floats a bit higher in the water with longer floats

15 minutes and $5 later... Floats for the Hawk. Also works on the Raptor.