I have just added another page to my site. A couple of keen canoists lightweighted my already light Eureka 155 Canoe.
The end result was that this 15ft 6″ boat came in at 34lbs (15.5kg).
Note the neat and very lightweight seat made of a washing line. It is important when drilling the holes to stagger them so you don’t end up with a “tear along the perforated line” type effect. A great approach by the builders! It also stops the crew from sliding all over the place. This behavior might have been at the bottom that some people thought the boat was tender where some experienced canoists thought stability was quite good even with the seats raised in height. Anyway, I have posted the user’s email in full in the link to the Eureka page at the bottom of this section.
The other methods they used to lightweight the boat were 3mm rather than 6mm plywood toughened up by using 66gsm (2oz) fibreglass over the bottom with a one inch overlap over the top chine. Also they did quite a bit of trim in Paulownia – a very lightweight timber originally from China but now being plantation grown in Australia and other countries.
The methods that were used are at this link
Eureka Page on Storerboatplans.com
And here is Peter Hyndman’s web diary of building a Eureka.
UBeaut OZ Woodwork Forums Eureka Thread