Today the kitefoiler was put into the water for the first time. It floated well and we were able to get a sense for its handling while recording load and speed data. The boat got up onto its front foils at around 16 knots, which required approximately 150 kgf of tension on the line. As the boat came out of the water, the force required to pull it diminished. Once up on the foils there were a few problems, so each towing run ended quickly.
The boat’s weight, measured just before launch, was 355 lbs.
The first graph shows the line tension and boat speed vs. time. There are 8 distinct episodes in which the boat is towed, and as the speed hits 10 knots, the towing force begins to level off. At about 16 knots, the towing force drops significantly as the hulls lift out of the water. The higher-speed tests usually end with the kitefoiler turning quickly due to a mechanical problem, which caused the load the spike and the speed to drop.
The second graph shows the line tension plotted against the boat speed (with some outliers removed).
Time: 3:30pm to 5:30pm
Location: SF Bay
Boat: Kitefoiler + Protector
Crew On Boat: Don, Joe, Dudu
Shore Crew: Damon, Richard, Jamie, Pete Lynn on Protector
Camera Count: 3 HD GoPros (handheld polecams (Don, Dudu), chestcam (Joe); 7D on Protector