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.
mechhacker|2 years ago
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