New Zealand Kayak Building

Plywood Racing Double & Great Auk Double
designed and built
by Brad Hayes

Brad has built 2 kayaks. A Great Auk Double and plywood stitch & glue racing double.

Brad's own design getting a workout

Great Auk Double

.The Great Auk Double was his first attempt at building. He had troubles with building outside and with Kahikatea which shrinks and swells a lot. The long cockpit is to accomodate two children happily behind the front paddler and well out of reach of the rear paddle. This was built as a family boat and has served them well.

Great Auk Double

Plywood Racing Double

The next project was the plywood double. In Brad's own words:

I didn’t want to build a stripper outside again until I can afford some cedar, which I have heard is not so moisture sensitive. Anyway, I designed it using the Carlson software which is available free on the net. Sent it around soem bulletin boards for an ‘international review process’ before starting.

I wanted a low displacement boat with the trim optimised for our 60 kg and 80 kg weights (60kg in the back - my wife wanted to steer as she doesn’t get to steer on our tandem bike). It is 6.8m long, 630mm wide, multi chined, and goes well. Oh yes - worth mentioning that it is reasonably light too - It is 25 kg with 200 gsm glass on the inside, 100 gsm outside, 4mm Okoume ply, has 4 bulkheads and is heavily reinforced all over the place. Very stiff. Could probably get down to 22 kg no trouble and still be heaps strong enough for the sea.

Some thoughts on relative performance of the two boats:

GAD needs more height in the foot area for the rear paddler - not quite enough for me and I’m only size 10.5
My wife and I get along at about 8 km/h in the GAD with payload of children (50kg) or camping gear (there is plenty of storage for us both to go camping) and about 9 km/h flat out when empty. In the ply double we do about 10.0 km/hr ie about 10% faster. There is a big trade off in stability for the extra 10% though.

The GAD is very stable - we have never felt uncomfortable whereas the ply boat feels tippy in harbour chop (Tauranga harbour). The GAD is also surprisingly wet for the rear paddler. I think the solution lies in an upward sloping deck between back of front cockpit and front of rear cockpit, like on my ply design.

Ply design is the opposite - wet in the front and dry in the back! But then I wanted a low profile front deck for less windage. Sits really low in the water which is great in windy conditions. We mainly use the ply boat in flat conditions where waves coming over the front are not an issue.

Ply design with two strong paddlers appears as fast as Duets, Hypernova’s etc; 12 km/h over two hour race no problem.
Must put in a plug for Mark Thomson’s (otherwise known as Squash Ball) Back of Beyond brand spray skirts (refer photos below). He does a superb custom job on any kayak accessory.