I sized my Guillemot cockpit up to the same size as my Chesapeake's. The Chesapeake has a big cockpit, but all the neoprene ww keyhole sprayskirts I've ever tried have fit it. 75% of the nylon skirts that I've tried fit it too.

Because of the different construction techniques, if you do a Guillemot style cockpit with the Chesapeake size outer coaming lip, you can pick up an inch or two more room than the Chesapeake has inside the coaming.

Shawn

: But make sure you can get a spray skirt to fit. If you just make a
: comfortable size opening, you may not be able to find a spray skirt to fit
: it - or you will end up paying a lot more to have one custom made. Some of
: the recreational plastic kayaks have "large" cockpit openings -
: and the maufacturers offers a spray skirt. So find a size you like and
: copy it.