I do very little "instabuddy" diving, in the sense of having absolutely NO information about the person before facing them at the dive site. But I have done quite a bit of diving with people I only knew from having them contact me and say they would like a buddy for some diving.
One of the few true instabuddy experiences I've had, I was the instabuddy . . . I showed up on the wrong day for a dive, and the captain let me on the boat anyway, and teamed me up with two other divers. One was on a RB, and they were friends who clearly had dived together before. I did one dive with the OC fellow, while his buddy sorted some gear issues, and that went fine. But when they both went into the water, it became clear that they really made little effort to stay together . . . and I learned that, in low viz, it doesn't take long to completely lose somebody who doesn't make any bubbles! I could see the two of them getting further apart, and I couldn't figure out which one to follow, and nobody was responding to signals. Eventually, I stayed with the OC guy (figuring a) he was more likely to need gas from me, and b) I had a much better idea of how to help him if he needed help) and we did about 20 minutes more underwater, never knowing where the RB guy was or if he was okay. I didn't like that AT ALL.
I've had two new-to-me divers (but prearranged dives), despite my ALWAYS careful dive briefing that, no matter what else you do, you are to STAY WITH ME, take off into the murk -- one at such high speed that I had great difficulty catching him. When asked later what was up, his answer was, "I thought you were going the wrong way." No signal, no discussion . . . he just turned 180 degrees and took off!
I think the best way to prevent a bad experience with a new buddy is to do a very careful dive plan, going over the goals of the dive, the roles of the divers, the gas plan, the profile, buddy separation protocols, etc. If someone is willing to sit through that, they're probably going to be OK Another good strategy is to look for a newer diver who admits they're new -- most of them will be very attentive buddies, even if your dives are short!
Edited because I couldn't resist adding, after reading some more posts above: If you really want to avoid bad instabuddy experiences, join a group of people who make working as a team the centerpiece of their diving strategy!
One of the few true instabuddy experiences I've had, I was the instabuddy . . . I showed up on the wrong day for a dive, and the captain let me on the boat anyway, and teamed me up with two other divers. One was on a RB, and they were friends who clearly had dived together before. I did one dive with the OC fellow, while his buddy sorted some gear issues, and that went fine. But when they both went into the water, it became clear that they really made little effort to stay together . . . and I learned that, in low viz, it doesn't take long to completely lose somebody who doesn't make any bubbles! I could see the two of them getting further apart, and I couldn't figure out which one to follow, and nobody was responding to signals. Eventually, I stayed with the OC guy (figuring a) he was more likely to need gas from me, and b) I had a much better idea of how to help him if he needed help) and we did about 20 minutes more underwater, never knowing where the RB guy was or if he was okay. I didn't like that AT ALL.
I've had two new-to-me divers (but prearranged dives), despite my ALWAYS careful dive briefing that, no matter what else you do, you are to STAY WITH ME, take off into the murk -- one at such high speed that I had great difficulty catching him. When asked later what was up, his answer was, "I thought you were going the wrong way." No signal, no discussion . . . he just turned 180 degrees and took off!
I think the best way to prevent a bad experience with a new buddy is to do a very careful dive plan, going over the goals of the dive, the roles of the divers, the gas plan, the profile, buddy separation protocols, etc. If someone is willing to sit through that, they're probably going to be OK Another good strategy is to look for a newer diver who admits they're new -- most of them will be very attentive buddies, even if your dives are short!
Edited because I couldn't resist adding, after reading some more posts above: If you really want to avoid bad instabuddy experiences, join a group of people who make working as a team the centerpiece of their diving strategy!