I'm looking for published data that describe the effect on glide ratio when an aircraft is converted from wheeled to float configuration. I suspect that the glide ratio goes down considerably due to all the drag from the floats and attachments, but an internet search turned up nothing.
I'm particularly interested in DeHaviland Beavers and Otters (which commonly have their gear switched between wheels and floats), but any source would be appreciated.
Note that at their configuration for best glide ratio, there is a drop in about 10% in glide ratio for the configuration for floats. This will differ for different configurations and operating conditions, but the basic effect of addition of floats will be a reduction in glide ratio.