David, The reply above holds some serious merit, and I might suggest that you have a go using wood (I take it they mean plywood) as suggested in the plans. The plans were drawn up with wood in mind and I would (pun) have thought that the finished article will be more than satisfactory. I have built several boats from very common or garden materials, 4mm ply, Hardboard etc and they were all fit for purpose, and none of them was very heavy. Lets face it, most boats need ballast of some sort or another, so building a super light hull sometimes is a bit self defeating. Hobbies must have sold thousands of those plans over the years. Get stuck in, follow the plans and there will not be a problem. Ashley