1948 F-27 Slo mo shun III

One of the more interesting boats in the Hydroplane & Raceboat Museum collection is a hull that, in spite of not seeing any significant competition, acted as a ‘proof-of-concept’ design that changed the sport.  Stan Sayers purchased his first hydroplane in 1938.  A 225 cubic inch class hydroplane, his renamed Slo-Mo-Shun I burned and sank during a test run in 1941.  When his next 225, the Slo-Mo-Shun II, was damaged in 1942, Sayers hired Boeing engineer Ted Jones to repair it.  Up to this point, the fastest boats were step-hulls which plowed through the water using a fully-submerged propeller. Jones had a different idea for a better mouse trap, and sold Sayers on backing it.  The result, was yet another 225 cubic inch hydroplane—the Slo-Mo-Shun III.

In 1947, Jones and boat builder Anchor Jensen began construction on a design relying on raising the hull and propeller out of the water.  This allowed the boat to ride on a cushion of air over the top of the water, instead of using brute force to power through it.  Hydroplanes had yet to capture the imagination in post-war Seattle, so there were not many other boats in that class to race against.  It was readily noticeable, however, that the result was 10 miles per hour faster than comparable boats.