Re: Grand Banks Dory.
Tell us what you plan to do with this boat -- carry how many passengers / how much cargo, what waters you'll boat in, how important sailing is, etc.
I've owned two solid-planked dories, a Banks and my current Chamberlain dory skiff, along with two ply sailboats and a larger glass sailboat.
There is a TON of mis-information and glorification about Banks dories -- the design was very specific for smaller boats that were stackable on deck, rowed for propulsion, and were loaded heavily with fish. Think "mini-pickup truck" for an analogy in the automotive world...
The problem with a 20' Banks dory is that it is getting close to being too large to row except under the most quiet conditions, so you'll be motoring or sailing most of the time.
Yes, they can sail -- but not as well as other dory (or similar) designs of the same size and materials. Yes, they can motor -- but with an outboard in a well, and slowly. If you don't like being that close to the noise and exhaust, you'll want a boat with a transom-mount outboard.
Banks dories can be a hot-button topic, and there are certainly those on this forum and amongst my boating friends who both row and sail the standard length versions - usually 16-18' . I expect we'll hear from 'em...
;0 )
But we also see new builders who get all starry-eyed about the reputation of the Banks dory, and build one for rowing. Surprise -- it is too tender and hard to row without 300lbs of ballast (remember it was designed to haul codfish). Then decide they want to sail it, but find it too tender. They then sometimes end up adding outriggers or whatever -- so the result is not the Traditional Banks Dory of their dreams...
So if you clearly understand the benefits and drawbacks of the Banks design and want to build -- great! But please look at your requirements and also consider some of the alternate traditional and modern designs that may serve your boating needs better.
"The enemies of reason have a certain blind look."
Doctor Jacquin to Lieutenant D'Hubert, in Ridley Scott's first major film _The Duellists_.