Sailor*Total Displacement*Sail Area*SA/D 215 397 72 20.91 210 392 72 21.08 205 387 72 21.26 200 382 72 21.45 195 377 72 21.64 190 372 72 21.83 185 367 72 22.03 180 362 72 22.23 175 357 72 22.44 170 352 72 22.65 165 347 72 22.87 160 342 72 23.09 155 337 72 23.32 150 332 72 23.55 145 327 72 23.79 140 322 72 24.03 135 317 72 24.29 I calculated the Sail Area / Displacement Ratio for various weights. To get total displacement(defined as the all up weight of the boat in the water with the sailor dressed) I used 15 lbs for the spars, 15 lbs for the blades, and 10 lbs for the rigging. My guess would be that hiking pants weigh 8 lbs, the rest of it 4-5 lbs, 12 total. So take your weight in your boxers. 183lbs + 12 for your clothing that is your all up weight. 195 Compare that to a 175 all up and you get a difference in SA/D of 22.44-21.64= 0.8 .8 as a percentage of 22.44 is 3.56% a 175lb sailor has a 3.56 percent advantage downwind and in light wind over someone who is 195lbs based on SA/D, (which is a generally a oft used and good predictor of light air and downwind performance, (not so much upwind)(not a measure of fitness). On a 1 km leg that is 35.6 meters, about 8 Laser Boat-lengths (assuming equal skill) (assuming SA/D is 100% relevant and significant) If you double the difference in weight from 195 to 155 you get 23.31-21.64 = 7.16% On a 1 km leg that is 71.6 meters, about 16 Laser Boat-lengths (assuming equal skill) (assuming SA/D is 100% relevant and significant) Click on the blog below to get the background info....

Ok. So how does the ability of the heavier sailor to sail the boat flat upwind fit into this equation? It is a well regarded theory that in a windy venue the gains upwind by someone able to hold the boat flat can negate the downwind advantage of a lighter sailor. I prove it all the time at my club in person, not on paper.

Actually it is the other way around. A lighter, taller, physically fit person who can hike the boat well (anaerobic strength static position hold, like a wall sit) combined with the sheeting, steering and wave torqueing body movements you see in 15+ (an/aerobic fitness like nordic skiing) on guys like Clay Johnson (watch his video (claysails.com) for the race at the midwinters). Clay moves his body fore and aft and jabs the tiller to leeward to guide the boat aggressively upwind in waves. There is a happy medium somewhere in the middle. Fitness means you can be lighter.

See Article " The Ideal Laser Body by John Dawson Edwards originally appeared in the ILCA N.A. District 5 web site maintained by the author at http://web.archive.org/web/20031102195123/http://www.jdecm.com/laser/ Body weights and sailor heights from the 2000 Olympics published. "Hiking Moment" is calculated by multiplying weight in Kg. by height in cm. A more accurate result would be to calculate the distance between the sailor's centre of gravity and a point about three inches below the knee, and then add that distance to the half the width of the laser, but this estimate will have to do. The data reveals that a weight of 78-79 Kg. (171.5-174 lbs.) is an extremely competitive weight for effective boat handling on a Laser. You don't have to weigh more than this. The Hiking Moment numbers show however that, in support of popular belief, you can't be short: the medalists in the 2000 Olympics were all between 178 cm and 187 cm (5'10" to 6'2"). Amongst other things, it seems I need to be about 3 foot taller to be competitive

In very light conditions I've noticed that the boats seem to get distributed by the weight of the skipper. You could easily just not race, weigh everyone and give out the awards starting with the lightest!

Two sailors, identical skill level, identical boats and identical weight, say 80kg would it be better to be a built, short 80kg or a tall lean 80kg, for somebody sailing laser full and radial.?

Laser hiking style is straight leg so: taller=more righting leverage=better (assuming both tall and short person have the weight distributed in the same areas, which most do)