Learn flight height in pump foiling: why flying high saves drag, what the foil does near the surface and how to avoid breach and touchdown. In 5 steps.
The honest answer: in pump foiling you fly most efficiently as high as possible, i.e. with the wing just below the surface and as much mast out of the water as possible. Then drag is smallest and you stay up longest. Scene guides put it like this: fly high on the foil, it lowers drag and keeps you away from touchdowns [2]; that way you get further with little effort. High here means: the wing lies close below the water surface.
A catch: near the surface a wing loses lift. A mathematical model of pumped hydrofoils describes the "automatic stabilisation" of shallowly submerged wings: when the foil approaches the surface its lift decreases, when it moves away it increases [1]. That helps you stay balanced but also means: if you get too high, you lose lift and sink again.
The perfect height is the highest one you can still control.
A second model shows why the interplay of front and rear wing matters: the front wing carries the weight, the rear wing provides stability of the pitch motion thanks to its long lever arm [4]. Both sources are models, not measurements on humans. Realistically you need many sessions until you hold height reliably (experience value).
One more word on expectation: holding height is the inconspicuous part of pump foiling because from outside nothing shows. Whoever can do it still pumps with much less effort, because every touchdown costs speed and every breach costs lift. So plan sessions in which you only watch height and aim for no record.
Fly slowly and attend to the feel: where does the wing lie? When does it begin to lose lift? Remember: near the surface lift decreases [1].
Milestone (practice): you recognise by feel whether you fly too high or too low.
Glide as long as possible before you pump. If the foil sinks too low, you pull your feet up calmly to reset the height [3]. That is the smooth way of regulating height.
Pump with an even rhythm instead of hectic strokes. One guide advises a steady cadence rather than aggressive, exhausting bursts [2]. The calmer you pump, the less height fluctuates.
Milestone (practice): 10 pumps in a row without breach and without touchdown.
Briefly unload the foil at the top of each pump. The same guide says: whoever makes themselves light at that point keeps the foil in the air with much less effort [2].
Practise varying flight height deliberately: slightly higher when gliding, slightly lower when you need lift. Whoever controls height controls pumping.
Milestone (practice): 30 seconds of flight at constant height.
Touchdowns and breaches can throw you off the board. The sharp foil is always close. Scene guides recommend vest and helmet and advise falling with the board in the direction of travel [2]. There is no injury study for pump foiling itself. In wingfoiling, which shares the foil hazard, the rate was 5.7 injuries per 1000 hours [6] (TRANSFER).
Practise only over deep, free water and with distance to others. This guide explains and motivates, it does not replace supervised training.
Let the foil "breathe": instead of holding height rigidly, let it swing slightly. The description of "hopping" in the guides fits this: the upward swing arises on the way up, speed on the way down [2]. If you use the swing instead of working against it, you fly more calmly.
As high as possible as long as you control the wing. Flying high lowers drag and keeps you away from touchdowns [2]. Near the surface, however, the foil loses lift [1].
Guides name 70 to 85 centimetres [2], an expert 70 to 82 centimetres [5]. Too short means more touchdowns, too long more drag. These are practice values from manufacturers and instructors, not measurements.
A model of pumped hydrofoils describes: when a shallowly submerged wing approaches the surface its lift decreases [1]. That stabilises height but also prevents you from flying arbitrarily high.
In a breach the wing breaks through the surface, in a touchdown the board lands. Both mean lost lift. The terms belong to the foil scene; there is no study on them.
Beach Start in Pump Foiling: From the Shore Onto the Foil Without Hitting the Bottom