If your waist harness is riding up then you need to buy a better one. My three year old NP now sits in the cupboard because it is obselete. It would ride up all the time, regardless of where I positioned it or how tight I made it around my waist. Even worse, when it slid upwards it forced by buoyancy vest to do likewise, nearly choking me! I no longer have those problems because I have updated my gear.
Low booms with a waist harness forces the harness to slide DOWN.
Perfect setting is 90 degrees, or perpendicular to your body when hooked in, hiked out, powered up.
Too high booms force the waist harness to slide up.
^ From an earlier thread; www.seabreeze.com.au/forums/Windsurfing/General/54-Knots-And-check-out-those-short-harness-lines/
Hans Kreisel does very well with low booms and short lines. I don't really understand what's going on.
I had thought that high booms and long lines puts a lot more of your weight through the mast foot rather than your feet, so I would expect his mast foot and foot straps would be further forward. It shouldn't make any difference to sheeting and ballast though.
I find longer lines and a high boom is more comfortable. I can hold my head more or less still while the board bobs around like crazy.
Who sails "new school" or old school?
We just go windsurfing.
Lots of freestyler's use high booms and LONG harness lines, to get that 90 degree off the body line thing.
Lots of speed sailors use short lines and low booms, but their harness lines are still around 90 degrees off the body.
I"m not advocating high or low booms, I'm just saying that keeping the harness lines around 90 degrees off your torso keeps the harness from sliding up OR down.
Lots of wavesailors use low booms and long lines.
It's all personal preference, but if the problem is waist harness riding up your torso, then lower your booms, or raise your harness.
He has the future generation boom, where the harness lines retract inside the boom when not in use. They call em, automatic spring loaded harness lines