aus230 said..
? does it hold when wet.
They certainly do Vic. Most surf and boogie boards use this on the leg straps. So do the bungy jumping ropes.

Although,,,,,,,, they need a bit of a tap out when full of sand/mud.
There is a formula for the strength versus length, of the attaching Velcro, (I copied a table for 50mm wide, double lapped) but I can't seem to find where I've filed it.

Worse still where I found the table. I reckon it was a 3M leaflet, from a trade day we had here in town.
For a "full rating" 50mm sticky back, requires 5 rows of stitching length wise (A row for every 10mm of Velcro) with a stich length not less than 4mm. I guess they are worried that it will tear through the hook side.