Gorgo said..Given that this thread is called "wingfoiling vs other sports" I think the dud session rate for wingfoiling is pushing 30%.
The two main culprits are wind dropping mid-session, meaning you have to sit and wait for the wind to come back, or paddle/surface slog back to shore. I had a couple of recent sessions with 40 minute waits for wind, and a heap with 15-20 minute waits mid-session.
The other biggie is the dreaded foil through the wing. All of my wings have foil scars and they've happened in the 3 years I've been winging (the most recent was today

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Both things can happen in fairly normal wing sessions. They're rarely associated with big crashes or disasters.
With windsurfing and kite boarding and kite foiling I would put the dud session rate at maybe 1%. In a combined 43 years I can only remember repairing one windsurf sail, one broken mast, and a handful of kite repairs. Most of the damage is associated with some sort of catastrophic crash.
It might be a matter of skill and luck. I find myself sitting on my wing board quite often, slowly drifting back to shore, when the wind drops. But my wife, who's a much better winger, just keeps foiling most of those days. My "dud rate" winging may be 10 or 20%, but her's is closer to 1 or 2%.
For me, the windsurfing "dud rate" is probably similar, but there are a few important differences. With a windsurfer, I can almost always sail back, since (a) I'm usually on a board that floats me when I cannot plane, (b) I usually stay closer to the launch, and can get back quicker when the wind drops, and (c) my windsurfing skills are higher than my wing skills. When (a) or (b) don't apply, for example because I sail a km downwind to get to a speed strip, then the dud rate goes up quickly. Coming back from the local speed spots that I sail to most often, I probably have to slog back about half of the time. But then, I usually stay there while the wind is good because it's so much fun

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Currently, I still get the biggest range when windfoiling. I can use the same sail comfortably over a much wider range than with a fin, and since my windfoil board is the largest board I use, I can always turn and slog easily. My upper end for a given sail is mostly limited by chop, and can easily be extended by switching to fin. The guy who spends the most time on the water at our home spot, where the wind goes up and down multiple times most days, switches between fin and foil most days. But my winging wife could probably match his time on the water with a single wing setup, if she would not come of the water when I do.