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moombabound
08-25-2008, 11:46 AM
Wonder if anyone has clocked a pro on radar. i.e. from shore or stationary boat, to see what maximum speed they reach between bouys on short rope. I've Googled for it, but nothing. Watching some of the short rope clips on Youtube...the velocity is just amazing. This was the subject of weekend chatter at the lake. Anyone heard? Somebody with engineering/spreadsheet skills has probably crunched out approximations at various speeds/lengths.

Double D
08-25-2008, 12:13 PM
Well there are two speeds for the pros. 34 and 36 mph so we know they are at that speed right behind the boat. I thought I remember seeing an article in waterskimag that said 65-75 mph for some slalom skiers. Someone please correct me if I am wrong.

zegm
08-25-2008, 12:26 PM
How long is the course? How far out are the bouys from the centerline of the course? You would think I would know this since I slalom ski down the course.

maxpower220
08-25-2008, 02:48 PM
http://www.jagersport.com/science_1.htm

http://www.palmbeachpost.com/sports/content/sports/epaper/2008/08/15/a2c_waterski_0816.html

Slalom Waterski Course Dimensions

Description Dimension Range
Total Length 849' 8 7/8" 847' 7 38" - 851' 10 3/8"
Starting Gate to Ball 1 88' 7" 88' 1 5/8" - 89' 1/4"
Ball 1 to Ball 2 Gates 134' 6 1/8" 133' 10 1/8" - 135' 2 1/4"
Center of Entrance Gate to Ball 1 96' 3 3/8" 95' 9 5/8" - 96' 9 1/8"
Ball 2 to Ball 3 Diagonal 154' 2 3/4" 153" 5 3/8" - 155' 1/8"
Entrance Gate, Center of Course to Ball 4- 4" 1 1/4" 3' 10 3/4" - 4' 3 3/4"
Center Line of Course to Turn Ball 37' 8 3/4" 37' 4 1/4" - 38' 1 3/8"
Center Line of Course to Boat Gates 3' 9 1/4" 3' 4 3/4" - 4' 1 3/4"
55 Meter Buoys 180' 5 3/8" 179' 6 1/2" - 181' 4 1/4"

At 34mph, a pro may reach 65mph. At 36, 68-70mph.

moombabound
08-25-2008, 04:37 PM
MAXPOWER220, I read the "Science of Slalom" link you provided. Good info, thanks. But the part about "The perfect line is a square wave" stumped me completely. Would have thought sine wave, not square wave.

deerfield
08-25-2008, 06:19 PM
From Palm Beach Post article: "Chris Parrish holds the men's world record for slalom: 1.5 buoys with the line shortened by 43 feet."

Holy smoke!

Sled491
08-25-2008, 07:50 PM
My understanding has always been that in a cut a skier would double there boat speed. This came from people I knew who jumped.

kaneboats
08-28-2008, 09:56 AM
That's a close enough approximation for me. You could use a radar gun to test the results. You could plot the skier speeds at various points during the cut and graph line length and boat speed . . . Or, you could just enjoy the smooth water.