Lets say, I want to build another canoe and that I have a perfect model of what I want that canoe to be (if only in my head).

I have a 15' Prospector Ranger and I do love the way that canoe handles both tandem and solo...... that is my model of perfection. But, what I would like is a smaller solo "play boat" for just dinking around. Maybe this solo canoe would be 13' (just saying)

Chestnut Canoe Company built a line of canoes called the Prospector. From what I understand is that the hull lines (shapes) of these canoes were all the same (similar) but differed in size. Their line of Prospectors canoes were:

Forest 12'
Fire 14'
Ranger 15'
Fort 16'
Garry 17'
Voyageur 18'

Ted Moores book has the table of offsets for both the "Fort" and the "Ranger". Is it just a simple matter of reducing the offset values by a certain fraction to create a smaller canoe having the same shape??? ......... for example a 13' Prospector could be created by multiplying the 15' plans by 0.87 (13/15)

Very interesting idea. I would think it is not a true linear relationship as a really short canoe would become too narrow at the waterline to have that nice Prospector stability. If you figure it out, please let me know as I am curious about the same thing. Best of luck.

Why not just do the twelve footer?

Typically canoes are lengthened or shortened by just moving the forms the required amount, for example if there are twelve forms, lengthening the distance between them by one inch would give you a hull one foot longer than the plans. Shortening works the same way. You really cant just reduce the offsets by say 10-15% to get a smaller hull because that would reduce everything including the waterlines and depth...making for a completely different and possibly very unseaworthy boat. By the same token, reducing or increasing the disatnce between the forms does not change depth. Reducing or lengthening by 10-15% is fairly common and is okay with most boat designers. For a solo playboat, I think this would be the way to go, as you keep the higher gunwales, which will be needed in rougher water/rapids. Ten percent would be the max I would go without sending off an email to Ted Moores for his okay. That would give you a 13.5' boat which would be just about perfect I woukd think for what you want.

Moonman.

If you stretch just the form spacing, which is OK, you need to stretch the stem forms also, or it won't fair out.

By computer enlarging, or reducing, you should adjust you form spacings accordingly.

Bruce Kunz's 38 spl. is his Merlin, computer enlarged, by 3.8% if I have the decimal in the right place.
The Merlin is built on 12" spacings, and the 38 spl, on 12.5"spacings

Both hulls have relatively the same handling characteristics, and waterline ratios, but the 38 has more capacity. Personally I love Bruce's 38 spl.

Jim