I wonder what happens on a prolonged wet journey - and I have done a few of those. And more to the point what happens after - is the tension recovered when they dry out ? Going to check my tank straps this weekend
I believe the strap is nylon, so it will not change dimension when it gets wet, but it will slip around more. So when you're tightening it up, it will pull up more evenly if it's wet / slippery - I believe this was the point 3Gs was making.