I think I seen a school in canada that uses a twin otter and do type ratings on floats but try this place
http://www.twinair.ch/site.php?menuI...kID=5&siteID=1 they dont have floats but I am sure if you have a float rating you just need to be type rated for an Otter then your float rating covers you for flying an otter on floats. good luck
