I understand that and everything else that has been said. The question isn't about getting into trim. I know what I have to do to get into trim and have no problem with doing that. The question is about staying in trim as you descent or ascend within the water column. Logically it doesn't even make a difference where you put your weights or how much weight you carry, it seems impossible to stay perfectly in trim in a (somewhat thick) wetsuit. The moment you descend or ascend, your buoyancy distribution changes and this changes your trim. It's a simple matter of physics. Yet nobody ever seems to even mention this.