: No matter how you slice it a kayak is going to box in your dog. If you dog
: can't come to grips with the tight quarters I would leave it on shore. If
: the dog is a must build a stipper canoe about 18 feet long with a wide,
: flat bottom.
I think that's why Matt mentions an open cockpit.

I don't think I would lengthen a single kayak for this purpose, but modify a double to suit my needs (if modification is even required). There are various examples of doubles built with an open cockpit.

A google images search for "open cockpit double kayak" turns up some results, including the Shearwater Boats Eider.