It controls the ride height by changing the pitch of the foils. The closer you are to the water the more angle on the wand which will put more angle on the foil and increase lift.
In fact, at 1:30 you can see a boat where the wand, for whatever reason, has stopped contacting the water and is out of adjustment. The boat begins to rise and without the input from the wand to dial down the ailerons at the back of the front wing, there is nothing to stop the boat from breaching. It thereby crashes. Windfoilers, kitefoilers and wingfoilers use their body weight to control pitch and ride height.
What function does the slender wand at the front of the small foiling boats serve?
It controls the ride height by changing the pitch of the foils. The closer you are to the water the more angle on the wand which will put more angle on the foil and increase lift.
In fact, at 1:30 you can see a boat where the wand, for whatever reason, has stopped contacting the water and is out of adjustment. The boat begins to rise and without the input from the wand to dial down the ailerons at the back of the front wing, there is nothing to stop the boat from breaching. It thereby crashes. Windfoilers, kitefoilers and wingfoilers use their body weight to control pitch and ride height.