I've been talking with some people - both on the kayak builders forum and the Delftship developer about whether Delftship did produce incorrect panel shapes or not. The most interesting (to me) detailed input has come from Toni V (thanks Toni) who took my design and moved the control points around while trying to keep the same lines. This was by hand so the result will not be identical, but it certainly looks pretty similar. Interestingly, the bottom panels as then developed by Delftship are *very* different shapes. For example, the ones I built from had a significant concave in the keel line at the stern. The new ones don't. I've sent these to Martijn, the Delftship developer - who is really friendly, thank Martijn - and will be interested to see what he makes of them.

You can see the differences even in the small picture above, where I've pasted in the linesplan and he panel development for the original and ToniV modified designs. Even at this scale you can see the designs are very very similar in linesplan but the bottom panels are significantly different. This is visible even though for some reason they are laid out different ways round for the two designs: keels together and sterns to the left in the original and sheers together and sterns to the right in the modified one. Check out the keel line towards the stern in both cases.

In both cases Delftship is set to show any developability problems in the panels. Interestingly it doesn't pick any up in the original (at this resolution) but does in the new model. Despite this he panels in the new model look a much more plausible shape to me, havin actually built the kayak now.

Click on the small picture for a full sized image where it is even clearer.