> Other than flotation in powder, crud,
> and/or slushy spring like conditions, does
> surface area mean that much in terms of
> ski performance?
> Is surface area only a means to create
> regidity between the shaped edges, provide
> a platform for mounting the bindings, and
> acts only as an efficient medium to
> separate the snow from the skier who
> basically is skiing from edge to edge?
> What is the inter relationship between a
> ski's surface area and effectiveness of
> edges on the snow ? Can these concepts
> [ if in fact they are correct concepts ]
> be separated? If not, how are they linked?
Wink, these are a very neat bunch of questions, and its pretty obvious that no one has definitive answers to all of them, but here's what I know.
First, there is the "simple" answer to your first question. Lets assume that the length of the ski is held fixed, and lets assume a normal flush base (ie, not like the catamaran example of the next paragraph). In this case, surface area directly translates into width, and everyone knows the major differences in performance between skis with 65 mm vs. 90 mm waists. For example, (a) when put on edge, fats try to torque themselves flatter more than narrower skis; (b) fats are slower edge-to-edge (ie, you have to move your knee more to achive a given edge angle); (c) if the snow is at all soft, fats reduce compaction and plowing drag dramatically, etc.
However, given your second question, I think you are thinking about something much more interesting. In particular, I think that the ultimate extrapolation of your 2nd question is that your are essentially asking (a) how a ski built with an extremely narrow waist (approaching zero waist width) might work, or (b), how a ski built like a catamaran with no solid base between the edges might work.
Todd gave the answer to (a), namely, even with a very narrow waist, there is enough load bearing area in the tip and tail to allow them to have enough float to perform reasonably well in all but very soft snow.
Unfortunately, we already know the answer to design (b): It would simply act just like a ski with a absurdly concave base (aka, a seriously "railed" ski). Even on very hard snow, such a ski is extremely twitchy when absolutely flat, and when edged, it locks into a carve with absolutely no skidding possible.
A solid base flush with the edges serves to smooth out transitions from one edge to the other, and permits some degree of skidding, however modest, which I would argue is essential to all skiers.
Thus, I think that the part of the ski between the edges does much more than serve as a place to mount the bindings (grin).
Tom / PM