Below is an article I wrote for Rodales Scuba Diving. It's worth reading if you solo-dive or are thinking about it.
Solo-Diving
by tomnolan
Date: 2001-05-10
Category: Misc Tips
There were always certain things that your mother told you never to do. Such as, never ride a motorcycle without a helmet, never swim right after youve eaten, look both ways before crossing the street and above all, never dive without a buddy. Well, I didnt listen to mom and Im still alive, so maybe there is something to this, solo-diving after all.
I had to ask my self the question, Is diving alone safe? I came up with several answers, yes, no, maybe. I wasnt helping myself much with my answers so I decided to take a scientific approach to it. I asked an instructor that I had known for years. He looked and me, raised an eyebrow and said in the most definitive voice I had ever heard, NO. I then asked him if he had ever dove alone. He said, NO! Then I reminded him of the time he went down the anchor line in North Carolina, alone to undo the anchor. He just looked at me, and again, he said, NO! So I decided to compare diving to crossing the street and asked a friend who was a police officer. I asked him if he thought diving alone would be safe. His response was expected, how should I know? I then asked if he thought if crossing the street was safe, and this is where I got the answer I was looking for, Sure its safe, if you dont get hit by a car. This seems to translate to, its as safe as you make it. Now I was on to something.
Ive been diving for more than seventeen years and have 1050+ dives in all kinds of conditions. I can only recall a hand full of dives where I actually came back from the dive with my buddy. It never fails, get in the water descend the anchor line and disperse like rattle snakes in the desert. OK, so that wasnt part of my PADI openwater course or any of the other courses Ive taken. I thought to myself, I need to do something about this, I kind of enjoy diving without a buddy.
I started to notice back in the early 1990s that there were technical diving organizations that were teaching a variety of courses where the curriculum claimed, Self-Rescue. This sounded pretty interesting, considering that I was diving by my, Self. After becoming a PADI Divemaster I took the IANTD Nitrox and Deep Air courses. Both of these opened my eyes to different equipment configurations and using technical equipment such as, reels and lift bags in everyday recreational diving. Before I knew it there was a group of us that would use reels, lift bags and surgical tubing on every dive we did. We would descend the anchor line and fan out in every direction. During surface intervals we would get together and talk about the different things that we saw during the dive. On the next dive I would find myself going to the spot were my buddy had been on the previous dive and again we would compare notes during the surface intervals.
The time had come for us to develop procedures for diving alone. Redundancy became ever more important. This meant the use of double tanks with isolation manifolds, not one but to lift bags, a pressure gage for each tank in the event that one tank had to be isolated and more than one way to get to the surface, this means, diving with a dual bladder BC or a single bladder BC and a couple of lift bags. Soon I had become even more skilled in the use of, bail out tables, underwater navigation and of course, self-rescue.
I used bail out tables in case I had to cut a dive short due to an equipment malfunction or other emergency. The bail out tables were nothing more than planning another, shorter multilevel dive. Not only did I use twice as much equipment on a single dive, now I was planning two dives for every dive I actually did. One for the dive I was planning to do and one in case that dive didnt go as planned and I had to get back to the surface.
Underwater navigation was the easy part. After spending 6+ years in the US Army and the better part of that in the Special Forces, land navigation had come easy, you do the same thing underwater that you would do on the surface. First things first. Mark off an area in a straight line and measure the distance. Now get under water and swim from point A to point B. Count the number of kicks from A to B, that is called the kick count and is used to measure distance. Swimming into the current take the kick count a multiply by two, swim with the current divide by two. The next part is land marks. Shoot a compass azimuth write down the direction in degrees on your slate and go in that direction.
Reels are used in case you forget how to use a compass or if you are in a cave, ship or any environment where you could get yourself into a black out situation. This is also where self-rescue comes in play. Never, ever under any circumstances, panic. This can kill a diver quicker than anything else. Panic can come quickly or slowly, depending on where you are, what you are doing, level of stress, level of confidence and so on.
My conclusion to the question, is solo-diving safe? I still dont have a definitive yes or no answer but I do have a definite but conditional, yes. It is as safe as you make it. The solo-diver needs to have the skills, knowledge of the environment for which he/she is diving, the right equipment for and the confidence to do the dive. If any condition is missing the dive could result in disaster.
It is important for a solo-diver to know his/her limitations, equipment and environment. I have never done a solo-dive beyond the limits of my own comfort, or with brand new equipment that I havent dove with before or if I were the least bit hesitant about the dive. Going beyond the limits of your comfort will result in unnecessary stress which can lead to panic which can lead to injury or even death. Remember solo-diving is only as safe as the diver making the dive.