: OK,
: My original thoughts on this are that a kayak should be stronger than a
: similarly built canoe.

Sage,

There should be no strength difference. Are you talking hull flex ?
You're probably thinking deckridge and closed loop cross sections ,
but an open canoe can be built just as "strong".

: Design changes

: 1. Rudder controls in both cockpits. This allows one paddler to sleep.

Go for it.

: 2. Longer seat straps. This may allow sleeper to lie down. This may be
: removed after wet exit trials.

Your call

: 3. Cloth hatches. All gear to be put into Dive type net backpacks. Pull over
: remove packs and have the lightest craft to portage. The skin in this area
: would be tied to the deck stringers. The cloth hatch can be laced and
: Velcro on top of this.

Good idea. PVC would work fine for this. The lighter load the better on a
lightweight, flexible hull while portaging. This is a narrow and shallow
double, so gear storage is ok but not great.

: 4. Nylon or poly cloth and a hapalon sealant. Something that can take some
: scrapes.

Nylon won't work for a folder. It will shrink a little after the skin is
removed rendering it useless. I haven't found liquid hypalon very scrape
resistant . It's pretty soft. Until proven otherwise, I like the scrape
resistance and overall durability of PVC/Polyester cloth. Plus. it's coated
two sides and the the hypalon is normally painted on one side only.
However, the hypalon is easy to repair by coating. The PVC is still easy
to repair, but must be patched.

: 6. Reinforcement between cockpits and a sail mount. This would be removed for
: the race.

What type reinforcement ?

: I have no problem increasing the wall thickness. This kayak needs to be able
: to land fully loaded in surf for me to be happy.

Thicker walls mean stiffer tubes. Stiffer or larger tubes are fine in a
rockerless,and near flat sheer racing canoe, but will resist the moderate
rocker( 4.5in) and sheer curve of the Combi. You could go with less rocker,
and less deadrise,but instead of heavier tubes, make it a multi-chine
( 3 per side) but still in a hard chine configuration so the existing HDPE
cross sections can be used.

Unlike the current extra set of 5/8" chines, go with 3/4" and have them hard-
attach at the stem plates making them a strength member unlike the ones I now
use. The additional chines would also give you a better floor to sleep on. Of
course, build and assembly times will increase.

Another option would be to build it for the race as an open deck kayak, Klepper
style, with washboards providing good deck rigidity and a 2-hole spray deck
when needed. This would allow you to lay down in the boat easier, and carry
more gear. It would greatly ease getting in and out of the boat for the zillion
portages. After the race, you could easily convert it back to it's original
frame configuration, and make a new skin. It would only cost $60.00 for the
second skin.

The Combi double costs about $500.00 to build, with an additional $50.00 for
the single skin. If you were to buy a Feathercraft double at $4000US and a
Kahuna single at $2,000, your savings would be in the $5500.00 range. Not bad !

The Combi, double only, was designed based on a request from a builder. As is
usually the case, he didn't build it, but I modified the design as the basis
for the Combi Double/Single and also the Symetrik. Now that the folding canoe
concept is in my head, look for it on the BBS in a month or so. it would be
sooner, but I still haven't had my West Coast vacation yet. Semi-snowed in.

I'm just running ideas past you. You get to make the necessary changes, and
there will be many based on your requirements. I normally strongly discourage
builders from changing my designs, but this special use application may be the
exception.

Enjoy,

Tom