So what kind of safety and buddy system practices have you really seen make the difference in bad situations or where the skill level is varied greatly?
I hesitate to reply since I don't follow my own advice all the time, but I'll take a stab at it.
I guess the most obvious would be the standard advice to dive one-up one-down and make sure your buddy has fully recovered before you dive. But it seems like almost no one in Southern California does that. I've had a lot of PFI and FII graduates on my boat who didn't do that. Our excuse is kelp and poor visibility. I've watched my buddy disappear into kelp with 10 foot vis and waited for him to surface. About the time I think he should be up, I look 10 years across the surface and there he is. What if he hadn't surfaced? Where would I have gone looking for him? If he had been using a float line then I could have followed it, but I might not have reached him in time to save him. And many divers prefer reels in the kelp.
Another thing to consider- even if your buddy is at least as good as you are, he's not going to be at his best when he sees you on the bottom dying. He isn't going to properly breath up and he isn't going to be relaxed. I suspect that is why Terry Maas invented the Freedive Recovery vest. His teen age son was diving with a buddy on the Kona coast. The water was clear and his buddy could see him from the surface, but he couldn't reach him.
I try to get my divers to compromise. We may not be staying close to each other while hunting, but we should look around and keep track of our locations so we can see someone wave for help. I think the biggest danger we face is when a white sea bass wraps the shooting line in kelp on the bottom and we have to dive to cut it out. Then we should call for someone to come watch us while we dive. Of course we still won't be able to see the guy on the bottom, but we'll know that he is pretty close to under us, and might see him black out just before surfacing. But we are back to varying skill levels. At age 80 I'm not going to be a lot of help if the fish is very deep, while everyone who dives with me could help me if I try to cut out a fish. Does the mean I shouldn't be trying to shoot fish? Maybe so. I hope we have a third guy on the boat and he can come watch the guy on the fish. I've seen guys on my boat turn down help when they had a fish tied up deep and there was a current. When they got back in the boat I read them the riot act and told them not to do that on my boat. Even if they don't care about their families, I don't want to use that emergency contact number that they gave me.
Another precaution is so general that its almost meaningless, but just don't take chances or push your limits. For instance Ive never felt a contraction that so many people talk about. Maybe I just don't get them no matter what, but maybe its because I'm so cautious. I don't like to surface feeling like I barely got there. My bottom times suck and I'm sure it costs me some fish, but I'm alive.
Last week I was diving with two friends on a high spot a couple of miles north of an island that is 50 miles off the mainland. There was a mild current, not enough to hurt my breath hold very much, but after a while my calves started feeling like they were cramping. In prior years I might have kept diving, but the nearest land was over 50 miles down current so I got back in the boat. My buddies shot 7 nice yellowtail to 35 pounds and I was really tempted to get back in the water, but then one of my young buddies came swimming up from down current of the boat and seemed to be glad to grab the end of the 100 foot current line that I put out when there is any current. I decided that this was no current for old men so I stayed in the boat and took photos they brought back fish.
But that reminds me of what I said earlier about kelp and poor vis being our excuse for a poor buddy system. We're so used to using that excuse that we don't change when the situation is different at open water spots with little or no kelp and poor visibility.
I doubt that this has been much help, but I don't have a lot of great ideas. If you do, please feel to comment or even criticize me. I've been married for 57 years so I'm used to criticism.
On final thing- I wish I could afford to buy a Freedive Recovery vest for every diver on my boat. I wear one every time I dive. I realize that it isn't a sure thing, but I think it might have saved two of the guys I mentioned in my original post. Unfortunately, Terry Maas is ceasing sales to the public at the end of this year, although I think he still will be selling another version to the military Special Operations forces. Yes, it costs $950 US, but a lot of my friends who don't wear the vest carry spearguns that cost way more than that. If you buy one is will be warranted through 2005. No, I'm not on commission.
Edit- I'm told that FII tells students not buy the FRV because it will cause them to push their limits. This seems inconsistent since a big part of the class is to learn to push their limits. I suspect that it could be a concern that students might not take the course if they bought an FRV, but I'm a cynic. You should take the course AND buy an FRV.