If a missing buddy is a common situation and "not an emergency", then it sounds like a failure on behalf of the crew to establish the appropriate sign and communicate it to the divers, to make this process more streamlined next time it happens and avoid delays in the rescue procedure. If the crew had lost buddy experiences before, they should have known better.
If a missing buddy is a common situation something is seriously wrong. Either with the divers, the divers training, or the conditions are such that they might want to rethink diving in those conditions until they are better equipped to handle them. That could be an equipment issue such as requiring lights or even a buddy line, but more often it is a skills and knowledge issue. Coupled with experience after obtaining the necessary skills and knowledge.
Much of what I see contributing to buddy separation is that the divers are seriously lacking in two areas. Number one is proper dive planning. And two, proper buddy procedures including a serious, frank, no BS talk on what the worst case results of each issue not being taken care of can be. A dead diver or divers. In the last couple months I have been able to dive in some new places for me and what I have seen is something I've been posting, writing articles about, and doing presentations on for over three years now. That is a lack of adequate teaching on just what proper planning is and what proper buddy procedures are. And the more I see of it, the more I'm convinced that it is because the instructors themselves are ignorant of it. Either that or they just don't care and I hope that is not the case.
Take for example planning. How many instructors tell their students that the moment they make a decision to dive is when the planning process should begin? And that all the prep from picking a site and calling a buddy to deciding who will bring lunch to the exit they will use from the water is all part of the "dive plan"? Tech, and especially expedition, divers know this and leave nothing to chance. Why should open water divers, even beginning ones, be any different.
If anything due to their lack of experience and training they should be the ones with the most detailed plans.
An open water dive with newer divers IMO carries as much risk to the poorly prepped diver as any expedition or tech dive. Expedition and tech divers have years of experience and training to fall back on if something is overlooked in the plan and can compensate for it with a variety of solutions they have ingrained in their minds and muscles. New and newer divers do not have that luxury.
As such they need more detailed plans and need to discuss contingencies and the what if's in much greater depth. The problem is they are not told that.
Be back with 500 PSI, listen to the briefing, stay with the DM, do a final check with your buddy, and talk to your buddy about the plan is often the most they are told. But they are not told how to make sure they come back with 500 psi using gas management, what to consider about the briefing and
use it to make their own dive plan, that the DM is not their buddy and may lead them into places they have no business being, and what to talk to their buddy about and how to make sure they both contribute to the dive plan.
They are also not taught the history of the buddy system and what the basis for it is and why it is so important. It is carefully put across as being for safety but that is sometimes lost in the hype of it being for meeting people, going places together, etc.. They are not told that it's to decrease the risk of a diver ending up being a bloated corpse being pulled alone from the water.
I see it all too often when instructors talk about the buddy system and then seemingly do everything in their power to demonstrate how unimportant it is. From not discussing the real risks of serious injury and death, to not buddying divers up in the pool in clear well defined teams, to leading them single file on checkout dives. Nothing is going to do more to decrease the importance of the system than showing them in no uncertain terms on their very first open water dives that it is nothing more than lip service. By not insisting that they stay in proper position the first time they are in the water they are saying "this is what we said but we really didn't mean it."
And again I think it's because they themselves don't know, understand, or appreciate the system for what it is and why. It's as if it was something they were told they had to say in their instructor course and that's why they do it.
What I would do if I were the OP is swallow my pride and get with an instructor who will tailor a class or workshop and not mince words or sugar coat the stuff he needs to know. Then I would see that I took that information and put it to use as soon and as often as possible. I'd start to be more choosy about dive buddies and make sure they understood what was expected of them and we would discuss what we would do in the event we got separated. Reason being is that every situation is different and the generic "look for one minute then surface" BS that is suggested is often nothing more than an "out" for poor planning and skills.
What if the divers cannot surface right away due to boat traffic or some other issue? What if they can hear their buddy but not see them? What if they had a clear plan to meet at the goal if they did get separated? All of these things would possibly negate the "one minute rule". But if they did not discuss this in detail and have a firm plan someone could follow the rule and end up hurt. It is easy to see a diver getting stressed and focusing on the rule, with no regard for the risks in using it, and surfacing into a boat prop or other danger.
If they had a clear plan that covered the situation and what they would do that risk could be seriously reduced or eliminated. IF they were using proper buddy procedures such as everyone swims no faster than the slowest diver, no single file swim crap, no more than a 1/4 turn of the head to locate your buddy, lights, and touch contact when vis went down or current increased then the separation would not have to occur in the first place. And barring a catastrophic event of some type, the separation protocol would not even come into play.
But it would still be part of the plan.
But we go right back to the divers not knowing or even considering it if they have not been taught how. And why. It is very easy to cover this in a short time in the classroom. Takes maybe two to three hours to go over all of it that is needed for open water divers in real detail. What takes a little longer is putting it into practice in the pool and in open water. The result of doing it is divers who are more knowledgeable, more confident, more skilled, and as a result safer. The end result of this is divers who enjoy what they are doing and dive more often.
Parts of the industry are putting the cart before the horse in focusing on getting people to get in the water fast and hopefully enjoy it enough to become safer and more accomplished. They hope that they won't get hurt or get the crap scared out of them and drop out. But still many do and so numbers are needed to replenish those who fall. Much like a Banzai charge. You decide a certain number are expendable and are ok with that as long as you can replace them. But there will come a point when those replacements will look at the carnage around them and think "not me buddy!" Then what do you do? I say use a little more thought, spend a little more time, train them better, and use those who would have previously dropped out to attract new ones who will also stick around.
Matt, I think will stick around. But he will have more fun and be a better diver if he addresses the issues that led to these last couple incidents. And he needs to find someone to help him do that and listen to what they say. As should anyone who is having issues like this.