That’s it. We’ve created a new type of watercraft:
The most amazing thing about it is how easy and fun it is to drive this thing. The long, articulated tiller extension is perfect for both steering and accelerating. It takes minutes to learn how to drive this motorized kayak, even in the standing position. The implications for fishing trips and touring are significant.
Gary Thorberg, from Farmington, Minnesota, mounted a 3HP outboard gas engine on his W500 fishing kayak. His goal was to break the speed record for this kind of watercraft, and he did it, big time, clocking 9.6 mph. Interestingly, there was no difference between upwind and downwind, which raises the possibility that Gary simply reached the upper limit of this motor’s speed, which is set by factors such as RPM, propeller size, pitch, etc.
9.6 mph is over twice the W500’s hull speed. Hull speed (a.k.a. Froude Number) is a constant number that increases relatively to the hull’s length at waterline. In other words, it’s harder to make shorter boats go at higher speed than it is to make longer boats to go at high speed. Gary’s W500 was planing. In comparison, here is a quote from an article about dinghies outfitted with outboard motors: “Another option is an outboard motor. Two horsepower per meter can reach hull speed. Ten horsepower per metre will put a flat-bottomed dinghy on plane. A 10-foot (3.0 m) dinghy with a hard V-bottom hull and a fifteen horsepower outboard can reach speeds of 25 mph (40 km/h).”
To put things in perspective, the W500 is about 3.5 meters long…
NOTE: This video shows an experiment, as part of a research and development (R&D) effort.
This is out second day testing of W500 kayak powered by a 2HP Honda gas outboard engine. This time we tested it in tandem, with a second adult on board. The W kayak seen in this video is loaded with about 390 lbs, which is over the maximum 360 lbs load we recommend. The passenger in the front is effectively protected from spray by a cockpit cover made of half a small tarp that cost $5. Not a single drop of water got into the cockpit during this entire voyage, and the cockpit cover wasn’t really necessary.
We kept a W paddle on board to help us pole while launching and beaching in shallow water, and as a contingency plan. The kayak was very stable, even when we turned at full throttle.
Following Sungjin Kim and Gary Thorberg, here is our beta version of a Power W500 kayak:
The 2HP 4-cycle Honda outboard gas engine is perfect for the job: It’s powerful, lightweight (28 lbs empty), user friendly (quiet), environmentally friendly (low emissions), and easy to use (throttle grip). Most importantly, one of the 2 models Honda offers features a 20″ long propeller shaft, which is an absolute requirement for the W500. Shorter shafts (e.g. 15″) won’t do. The Power W500 went at high speed even when another passenger weighing 115 lbs came on board. Driving it feels pretty much like driving an aquatic motorcycle – it’s fun, and exciting. Getting used to steering with the tiller handle behind your back takes some time, but eventually it isn’t hard, and the sitting-riding position feels comfortable.