DandyDon:Thanks Otter!
I've had buddies float up on me and been able to catch them safely and bring them back down, and - I've had them get away from me entirely. After a slow ascent, skipping the SS, I'd take them back down to 15 feet for 5 or more minutes. I've seen that idea supported and criticized, but as long as we're together - it seems safe and helpful.
Letting a buddy ascend alone tho does create two solo divers. As much as I like to think I'm better off on my own with my pony than most of the buddies I've had, that's just not true.
Its funny, the most often cited reason for it being safer to dive Solo vs. with a buddy is the quality of "the buddy". A lot can and has been said about how you pick your buddy (and there are situations where are choices are somewhat limited -- teaching is an obvious one, assigned buddies are often another cited), so ignoring that for the moment.
I find it interesting/disturbing that for a Sport whose central tenant is that "anyone can call a dive at anytime without fear of ridicule" [which implies to me a team-centric sport], the concept of team risk is ignored. The more experienced diver might be at greater risk (vs. solo) with a novice diver, but the novice diver is certainly at significantly less risk diving with an experienced diver (vs. solo).
One could do the analysis of the (probablity of a failure occuring) x (the probability of that failure being handled successfully by a novice diver) as well as the (probability of the buddy causing/having a problem) x (the probability that the experienced diver wouldn't be able to "protect" him/herself), but my guess is that overall, there is less net risk to the team together than individually and that the increased risk to the experienced diver is not that significant.
It seems like all to often it comes down to "how does it affect ME"