> Perhaps the designer built a prototype and tested it exhaustively

It's true - I have had a set of offsets (my Borealis project) on my own website for almost ten years without yet getting round to building the prototype or even being entirely sure of how to build one or two parts. My return to this forum is possibly presaging actually getting round to it... But *someone* has to build the first boat to any design, otherwise there will be no new designs, paid-for or free. I will always put out the offsets of any boat I build (or plan to), along with my rationale for building it that way and my assessment of how it paddles, along with how I would do it differently next time (no prototype is going to be perfect first time). A major reason for starting with free plans is that no-one is going to be badly put out if I modify those numbers and publish the results. I wouldn't feel comfortable doing that with plans I'd modified from a paid-for design and that's a major deterrent from even considering using such a design as a starting point.

I'm an open source fanatic. I wouldn't want to build a boat if I couldn't publish the design for others to use any more than I want to write software and only distribute a binary form...

> It's important to distinguish offsets, outline drawings or a study plan from fully detailed plans complete with skantlings, bill of materials and instructions

Yes, I'd always prefer to start from offsets rather than full plans since I am inevitably going to modify things. Raw numbers are always going to be the easiest starting point and the most versatile.... I built my first boat from offsets (and the instructions in Nick's book, later supplemented by several more books and quite a few methods of my own invention - there's always more than one way of doing a thing). Building to a fully specified set of plans is always going to produce a boat just like the original which (to a certain mindset) is hardly better than just buying a plastic one ;-)

So what I look for is plans that are not merely free (as in beer) but free (as in speech) published under something like a Creative Commons license.

Andy