Hydrofoils have been exploding in popularity in watersports. It used to be seen as a thing to do on light wind days, because it lets you go faster than the board usually limits you if you can't get hydroplaning. Hydroplaning takes a lot more wind power than hydrofoiling.
But, they've been pushing the windsurf gear to 40kts on hydrofoils. That's without adjustable control surfaces like these boats, just steering with body weight and sail trim. I personally have gone 23kts or so and it feels much much faster than when you're on a fin, and you are constantly moving your weight to keep from slapping the water or getting too high for the foil then crashing.
That is accurate, however, once within the same high wind and weight, hydroplaning gets ahead. That is due hydrofoil drag effect being so much higher than a regular fin. Same reason why windsurf speed record is 55kts while the windfoil record is somewhere near 37kts today.
IIRC Thomas Goyard hit 41kts on the foil, but may not be "official".
The speed canals where they hit really high speeds on fins are in special areas that most people will never be able to experience that have no wind disruptions and are very shallow canals to keep the chop down like in Luderitz, it isn't an open water speed: https://www.youtube.com/watch?v=jt3DQNUJXkc
The races, which have fin and foil against each other, have been in open water state (more real world for 99% of windsurfers), and in those conditions fin vs. foil are very competitive, with foils pulling ahead in the turns due to a lot less resistance and better ability to get back upwind compared to a fin. There's been a lot of debate on even allowing them to compete in the same races as they currently are allowed. They can both do 30ish knots in the same conditions, with the foilers getting away with smaller sails.
https://www.youtube.com/watch?v=jsUDkg2d5tE
Yup, that's the speed. It can be dangerous. During races they are required to wear impact vests and helmets.
Another innovation is a new kind of harness for the connection to the sail that releases above a certain force. A lot of the injuries are related to still being attached to the sail and being thrown into it during the crash, where you hit the hard carbon boom or mast instead of being flung clear into the water. That harness prevents that kind of catapult.
But, they've been pushing the windsurf gear to 40kts on hydrofoils. That's without adjustable control surfaces like these boats, just steering with body weight and sail trim. I personally have gone 23kts or so and it feels much much faster than when you're on a fin, and you are constantly moving your weight to keep from slapping the water or getting too high for the foil then crashing.