Computers and Decompression Planning

[Deep Blue]

I would like to open a discussion on computers and dive planning.

First, in my opinion, I think that wrist mounted computers are fine for most recreational divers who have no desire to use tables and dive well within the recreational limits. They are especially nice for divers doing multiple day diving such as on a liveaboard.

My biggest concern is with the newest generation of multigas dive computers. I believe that if you are going to commit to doing a planned decompression dive, a mixed gas computer is not a good tool for executing or planning the dive.

Decompression diving is a major step up from simple recreational diving. I am concerned that the availability of multi gas computers can embolden recreational divers to not plan their dives and simply rely on the computer to get them back to the surface safely. What they do not realize is how quickly decompression time stacks up at depth. Also, they are not appropriately equiped with redundant equipment and an appropriate buddy. At the risk of igniting a firestorm, you need to Do It Right, or don't do it at all.

There is a tremendous amount of planning that needs to go into a planned decompression dive, including; gas selection(both bottom and decompression gasses), gas planning, contingency planning and bailout procedures. There is another issue that recreational divers are not prepared for mentally, the fact that the surface is no longer an option if something goes wrong during the dive. If you are executing a decompression dive, you are under an overhead just as surely as if you had steel hull plating over your head.

I believe that there is a paralell between decompression diving and rebreaterhs. Just as there is a tremendous amount of predive work that needs to go into a rebreather before you use it, which doesn't make it appropriate for most (read 99 percent) of divers, the same holds true for decompression diving, both in that a tremendous amount of planning needs to be done and that it is not appropriate for 99 percent of divers.

When it comes to decompression diving, I believe there are 2 computers that you can rely on. The primary one is between your ears and you ensure its reliability through taking classes, outside study and experience. The other, is the one that you use to plan your decompression diving and create your dive tables BEFORE you get into the water. This one totally relies on you, it will only be as good as the information that you put into it.

Well, that should get us started, I will post later on what exactly goes into planning a dive, as will lots of other divers on this list.