Doing a 360 has been done in ski shows. The trick is to use a high pivot (performed before towers were common) on the boat and doing an "S" turn by the driver. The driver goes into a power turn and accelerates the skier and then does a power turn in the other direction and the boat goes behind the skier and resumes the original direction. I'm sure a 75' rope was used. That was the days of the wooden saucer with a small step ladder on it and the skier with the kite.


In the late 60's, the Cyprus Gardens El Diablo was the must have ski. It had two sets of grooves on each side of the ski that prevented lateral movement. The concave form came later and much better improvements when manufacturers went away from wood. I maintained my ski each year with waxing on a regular basis with carbana wax. Someday, I will hunt it down from the attic.

http://www.trademarkia.com/el-diablo...-72288009.html
http://www.kijiji.ca/v-water-sport/b...ationFlag=true