A Greavette Muskoka Disappearing propeller boat or "Dippy" as it was affectionately named, was originally designed as a work boat for the logging industry. The propeller assembly could be pulled up inside the keel for easy movement over log booms and rock outcrops making it a perfect match for the Muskoka Lakes. This John Bull model was powered by a one cylinder gas engine which also inspired the name "putt putt". These boats were easliy adapted for recreational purposes are now very attractive for antique boat collectors.