I found this ski surface area calculator (with numeric integration) while browsing :

http://www.freshiez.net/skiarea.html

Just out of curiosity I made a few measurments on my 165 cm race carver ( 117-65-100 ) and found the contact lenght to be 147cm, 111mm at the tip and 99mm at the tail. The area came out to be 1152 cm^2.

Following up on that I came across this ski length guide :

http://www.villageski.com.au/demo.htm

After marking my weight as 75kg, intermediate level, and short radius turns the total index came out to be 1150, equal to my ski's surface area ! Now I don't know if that is pure coincidence or if the length selection index is actually roughly based on a surface area criterion.

Most people I know will say a ski's surface area is of little importance if you're not skiing powder or crud. I think I disagree with that. My assumptions are :

1) If you ski with a carving style contact edge length should probably be a greater priority for better edge grip at higher speeds. But what if your skiing style is skidding or steering ? In that case more surface area would equate to more friction which in turn would lead to the skis feeling heavier while turning.

2) Provided that the ski is planing over the snow and not sinking, extra surface area should make the skis feel less wobbly and more stable at high speeds. Straight line acceleration will be slower.

Do you think my assumptions are correct ?