Design exercize: Peaches, an 11 foot catboat
by John MacBeath Watkins
The idea here is to design an easy to build catboat that will also be inexpensive. The sail is a Laser practice sail, which saves at least $300 over a similar sized sail. This means keeping the waterline narrow enough for the boat to be pushed by 7 square meters of sail. We don't want the crew to have to hike too hard, so I've given it plenty of flare above the waterline to put the skipper's weight out there without too much stress on the stomach muscles.
The boat is stitch and glue, with two panels a side, and I've managed to get the panels to develop with fairly low stress. In fact, there's less stress in the panel that forms the bottom and the catboat bow than there is in the side panels. Still, you'd best build with 4 mm okume plywood, which is light, fairly flexible, and comes from sustainable plantations. One problem is that the boat is too wide to fit into my 1997 Nissan's bed, so I'd have to cartop it. All-up weight is going to be around 100 lb., and you only have to lift one end at a time, so that shouldn't be too bad. Cost of construction with the sail should be less than $1,000.
Now, I just need free time (I work six days a week), a space to build it, and a bit of cash to make the thing...well, they say man's reach should exceed his grasp, else what's a metaphor?
Update: On the advice of Tom Price, I've raised the freeboard, and I think that makes the boat better: