I've been windsurfing on and off for a good couple of years now...but I still cannot get my waist harness to stay at my waist.
I've tightened it to the point where if it slips up it just compresses my lungs and I can't breath...less than ideal.
Nothing seems to help!
Any tips to stop this happening?
(bar the obvious of getting a seat harness)
aj
i had an older style waist harness which did the same, ride up float all over the joint. Could never get it tight enough for it to sit still. I thought now's the time to stop being a tight arse and invest in a new one. Best thing i did. easy to adjust and firm.
Drop into any windsurf store in Perth you have at least 4 to choose from and try them out. well worth the investment.
If you follow subsonics tip you might need to invest in a bigger board. they cost more than a harness i think 
I had the same problem, was at Geralton walked into wsurf shop, and rick the owner says the problem with you is you don't have a waste, just use a seat harness 
I had a Dakine waist harness which kept doing that and I compensated by shorter harness lines.
Eventually had enough and went for the seat harness.
Recently bought a kite waist harness which doesn't slip. Just contoured differently I think.
Could be stance?
I had this problem when I first moved from seat to waist harness.
Did a clinic at Moon beach and the instructor said "ass-in not ass-out".
"Ass out" causes your lines to pull up on the harness hook making your harness ride up.
"Ass in" causes your lines to pull away from you and not up.
Might be worth a try 
Select to expand quoteAUS729 said..
Could be stance?
I had this problem when I first moved from seat to waist harness.
Did a clinic at Moon beach and the instructor said "ass-in not ass-out".
"Ass out" causes your lines to pull up on the harness hook making your harness ride up.
"Ass in" causes your lines to pull away from you and not up.
Might be worth a try
I think you raised a very valid point, AUS729. I adopt the stance yacht sailor used by hanging my weight off the boom, and half my body is off the side of the board. I believe your waist harness will ride up if you choose a more vertical posture ie. "Ass out".
Of course, your body shape does matter a lot. May be that is why lady sailors prefer seat harnesses ?
Could be worth trying a couple of different brands. Dakine make great harnesses but I couldn't ever get their waist harness to stay down but find the pro limit equivalent a great fit.
Saying that stance does make a big difference.
