What does “5 at 15 off” mean? These number scores are are some common lingo used in the water skiing community. To a beginner in the sport the numbers tend to come off as confusing, but it is actually quite simple once you understand what each number represents. The first number is the number of buoys cleared. In a traditional slalom ski course there are six buoys. So the score of “5 at 15 off” would indicate that the skier completed 5 of the 6 buoys. The second number is the amount of rope the skier was able to take off the end of their ski rope. The more you take off, the more difficulty is added to clear the buoys because you are then closer to the boat and have less time between each buoy. A standard water ski rope is 75 feet, so taking 15 feet off then becomes 60 feet. Standard lengths to take off are 15, 22, 28, 32, 35, 38, 39.5, and 41 feet. Going back to our example of 5 at 15 off would simply mean that the skier took the first loop off of their ski rope to then have a 60 feet in rope length and successfully cleared 5 buoys.