Many thanks Paul, this is really useful and interesting post. It got me rethinking the design. My hand carved attempt had major stability problems, so I was thinking i'd put wider flare and two keels angled outward on this attempt.

The aircraft carrier analogy is brilliant, and I can see a number of advantages, but would it suffer from the same 'splits' with both ships moving apart? Any ideas on where to start with a design like that? How would you calculate where to put the conning tower ... or just sketch it, build it & trial and error?

Thanks again for the reply, I proably need some more time to digest the concept. Certainly having fun with this anyway, the only downside being... it well past 1am and I'm thinking at 60knots.

: Standing with your legs wider than your shoulders gives good
: balance on land, but trying that on water will simply force the
: boats further apart, and in seconds you'll be doing the splits
: on the way down to the water. Then, when it is time to take your
: next breath, you'll wish your foot release was positioned where
: you could reach it.

: So, let's look for a design which keeps you upright. Only the part
: which is underwater is going ta affect your stability, so if you
: are committed to having water shoes which look like kayaks just
: make them a bit taller and carve the part above the water to
: look like anything you want--- tugboats, ocean liners, swans,
: whales and porpoises are just a few possible designs.

: Underwater you'll want something with a keel which has a good
: surface area to resist the side-slipping that you are going to
: encounter are you transfer your weight from leg to leg.

: You'll also need to worry about displacement. Each float must be at
: least large enough to carry your entire weight. No sense
: capsizing at your first step.

: Then you want to have the hull shape help your propulsion. It
: should resist moving backwards when submerged more (as you put
: your weight on it) but be easy to move forward when less weight
: is on it.
: It sounds like you'll need a seriously asymmetrical design, and
: make mirror images--- one for each foot.

: Have fun with the design. :)

: I'd try to keep the centerlines of my feet no more than 9 or 10
: inches apart. That means some very narrow pontoons. To get the
: displacement you'll need the hull will need to be very narrow,
: long and deep. At a point where half your body weight is
: displaced, the hull shape will need to flare wide so you can
: displace your total weight on a single hull while you move the
: other foot forward. Very unlike the hull lines of a kayak. If
: you look at the lines of an aircraft carrier you might be
: heading in the right direction. The conning tower is way to the
: side and the deck flares away from the hull. Now picture a
: similar shape, but move the keel so it is directly under the
: conning tower. Ake two of these models--one with the conning
: towre on the left and one with it on the right-- and put your
: feet where the conning towers go.

: That gives the cross section. From the top view I think you might
: want to consider a Swede-shape design. That would put your
: center of gravitywell behind the centerline of the boat. With
: the bow more bouyant than the stern it might be easier to plant
: your weight on one sidewhich would have more drag and resist
: moving backward while you slid the other foot forward.
: Using a strap between the two hulls would keep you from doing the
: splits, but it would also limit the length of stride, and
: perhaps the forward glide. A strap would also limit your ability
: to shift weight from leg to leg.

: Just some thoughts on this. Hope they help.

: PGJ