I was taught on my knees, and I found it so hard to keep my balance. When I became an instructor, I started out teaching on the knees as well as it was all I had ever been exposed to. But because I was STILL having trouble staying upright on my own knees, I would get myself into a neutrally buoyant position to watch while making students kneel. I know, weird right? It was weird, but I'd get these horrible foot cramps from trying to stay kneeling for hours, so I'd start out kneeling everybody, demo the skill myself while kneeling, and then as students would practice the skill, I'd get myself horizontal for comfort. Naturally my students began to imitate my horizontal posture and I noticed how much more comfortable everybody was when they were like that, so I started demonstrating skills and allowing them to be performed in a horizontal position. I checked the performance requirements listed in the standards carefully to make sure that there was no specific instruction regarding position while performing skills, and as there wasn't, I gradually made the switch to what I consider 'nearly neutrally buoyant' instruction. Related to this but somewhat later was my relief at the change in standards so that it was no longer required for the fin tips to be touching the floor of the pool for the pivot skill--I always had THE WORST time keeping those fin tips from coming up due to the ideal weight distribution I employ for diving. I can easily bend my hips to have my knees touch the bottom for this, but straight-leg pivoting from fin tips.... well, every time I had to do it I had to concentrate, hard! I have to admit that I sometimes felt embarrassment and wondered if I was a bad instructor because I could not easily and fluidly demonstrate this fin pivot skill! Now I have all my students do their basic skills work in a horizontal position.