Since you are typically carrying two independent gas sources, you cannot simply "breathe one down."
Your cylinders should sit perfectly parallel to your torso. The valves should be tucked just under your armpits, never sinking below or floating above your body. Sidemount- Principles For Success
When you clip on a full tank, the valve should sit just below your armpit, and the bottom of the cylinder should rest neatly under your buttock, not behind your hamstring. Since you are typically carrying two independent gas
But here is the hard truth:
Never try to clip the lower bolt snap first. It is physically impossible to get the geometry right. But here is the hard truth: Never try
Sidemount puts valves behind your head. That means you cannot see them. You must reach, identify, and operate them by touch alone. Practice left-hand shutdowns and right-hand cross-reaches until they’re muscle memory. If you can’t shut down a free-flowing reg in zero vis, you’re not ready.