As a statement of absolute fact you're off the mark there Jim, no matter how much I like how your courses are designed.
Buddy separation can and does happen. If you want to argue with this one perhaps we can end up in waters where I'll show you I'm right.
Don't be too dogmatic, it's rarely helpful.
J
Be glad to. How would this separation occur? Vis, mechanical failure, lack of buoyancy control on one persons part, speed, strong currents? All can be adjusted for including by calling the dive. Some conditions you just don't dive in or you decide to dive alone. But if you decide to buddy up everything that goes with that needs to be considered. And that begins on the surface when you decide to dive in the first place.