Not sure about all kiters, but over here we call it a "good day" when its 20 to 25knots as we a very nicely powered and the ocean and waves arent too massively bumpy/white capped out.
I see you guys must get a bit frustrated that we can be so powered up in smoother ocean/wave conditions, compared to your "good day" finally powered and planing 35knot washing machine conditions.
We can always go out in 40knot winds on a 5m kite, but why would you want too in messy ocean slop? Kinda like going water skiing, wakeboarding or surfing in messy 1m white capped conditions

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I guess its the difference between the two sports, you guys love the big white capped bumpy stuff where kiters , like surfers I guess, prefer the smoother glassy waves/conditions , but we can still be fully powered.