Captain Larry Jarboe from Wavewalk Adventures in Key Largo, Florida, drives his “White Knight” workhorse S4 cat-skiff powered by a 9.8 HP 2-cycle Tohatsu outboard motor, outfitted with a 9″ pitch propeller.
Larry easily gets to a 17 mph speed, which is probably a world record for vessels that are officially designated as kayaks, such as the S4.
He drives sitting in the side-saddle position, similarly to the way that he’s been driving dinghies and other small boats for decades – No stability problems, and no control problems, even in the chop. Most people who drive the S4 and other Wavewalk kayaks / boats do it in the riding position, with a leg on each side of the saddle seat, similarly to the way that Personal Watercraft (PWC a.k.a. jet-ski) drivers operate these vessels.
Generally, 2-stroke outboard motors are lighter than comparable 4-stroke outboards, which makes them more portable.
9″ is the highest pitch for propellers that fit this motor. A propeller with a higher pitch would have probably added some speed to Larry’s record. In any case, 17 mph falls within the upper range of speeds achieved by small, lightweight boats with propellers of such pitch.
Practically speaking, this performance coupled with the S4’s capability to carry on board up to three anglers and their fishing gear, puts it on par with Jon boats, skiffs, and even some bass boats.
The S4 is an ultralight car-top boat that can be launched and carried anywhere, as well as paddled in extremely shallow water, and it is most seaworthy. These facts offer its users an advantage that neither conventional nor new boats do.
Note that Larry is a most experience boat driver, and driving such a small craft at such high speeds requires skills that not anyone has. This is to say that we do not recommend such powerful motors for the S4.