How does one lose such kit? Serious question.

yeah, solid swell running today

If it's windsurfing gear, then yeah. I'd never tether myself to windsurfing gear. Foiling, I'd always be tethered.

Well not impossible, you could put a leash on the front of the board or mast and tack quite happily. Impractical!

Ralaoups said..
I know someone who tried and is really convinced :D

He tried just once, on flat water.

Note that kitesurfers do not use leashes because it is extremely dangerous when you jump, the board will come back to hit you.

Also, I cannot count the number of times I ended up under my gear after a wipeout, being pummelled by breaking waves. With a leash, I would have risked being tangled up underwater.

This said, It may be useful for specific uses, a bit like downwinding: windsurfing in strong winds, long distances, no jumping no surfing.
In the thread they mention Sarah Hebert using a leash between her harness and wishbone handle for her crossing of the atlantic.

Also i like this translation.

"Honestly, the day you refuse on a loop or on a jump a little too high, you must cry for your mother!!!!"