Can you provide a link to John's presentation? I must've missed it.

In the meantime, I'll try to unearth a shot or two of an open Pax 20 that was built to race in the Texas Water Safari. That's what a couple of the boats in the photos you posted are built for; the fancy one is Chip Sandresky's boat, don't know the design but I believe it was s'posed to be a tandem or triple kayak. He used to be a regular on this forum, now lives somewhat near me but isn't into small boats at present. I could conceivably get you two in touch, however.

We see lots of long skinny go-fast boats here in Texas that are open as canoes, they're pretty common in our very lively race paddle community. Open boats are desired for the marathon downriver races so paddlers can jump in and out easily for portaging and/or replenishing consumables as the saga plays out. A boat with a reasonable bit of stability conserves energy over things like surfskis and K-1's that require constant attention to keep upright, although some 'skis have completed the TWS (265 miles), and a smattering of K-1's finish races like the Colorado 100 (miles).

I have a guy threatening to give me a bare stripped hull of a Redfish Return, and if it comes to pass, I plan to make an open boat out of it as a fast fishing boat.