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.

[scubert]

Gert,
I think this problem is symptomatic of the whole dive industry right now. There exists an attitude of "no problem" to all of diving right now, perpetuated by the big training companies. Divers can advance through courses too quickly without actual dive experience, and without the repetition of even basic skills needed to turn actions into reflex-actions. Mix-gas computers are another sign of this ever softening skill requirement.
I am always suprised when people don't have ANY dive plan, even an informal one. I won't pretend that I sit down at my computer and plan every dive I make before I make it, but I do have an idea of our max depth for a dive and my air comsumption at that depth and the reserve I want to leave. I do use my computer as a guide throughout the dive, but then I rarely do deco, and if I do it's only a short hang with the same gas used on the bottom.
While I think a lot of DIR/GUE procedures are fantastic, I don't always think you need to 'do it right' to do it correctly. However, something needs to be done to stiffen the big training agencies requirements, or possibly lengthen the training again, or more accidents WILL begin to happen

[TomG]

My opinions on this subject are:
It's an example of supply and demand. Divers want the latest and coolest equipment on the market, they want to be trained in the shortest possible time, for the least amount of money, and the schedule better fit mine, not the dive shop's. If not, they'll find something else to spend their money on, and it won't be diving. Isn't this the same in our everyday life? Everyone wants things done cheaper and faster. If the equipment manufacturers or shops would only sell multi-gas computers to those who "have the training" to "do it right", that would be the ideal world.

We all know that the average joe who walks into their local dive shop isn't necessarily doing deep diving, where multi-gases are used. Gert, you said it yourself, only 1% of folks really should be into decompression diving.
I'm beginning to see this board going the way of the old milwaukeescuba.com, in that the discussion seem to revolve around deep, mixed/multi-gas, deco, DIR, if you're not diving deep, you're not diving, "mine are bigger than yours" mentality, extreme diving.

I also see lots of comments from some posters who have to tell how many folks they "have saved" or how deep they've been, or how dive shops are ripping people off, you can make it cheaper than the dive shops sell it for, etc. I believe that was the downfall of milwaukeescuba.com, and why the average diver gets out of, or doesn't stay with local diving, and will be the downfall of some smaller dive shops.

Gert, seeing that you're now a dive shop owner, if someone comes in and wants to buy a multi-gas computer, perhaps with the intention of using the multi-gas feature later, or not using it at all, would you still sell it to them?

Sorry for the ranting,

Tom.

[scubert]

Hi Tom,
I don't think you were ranting at all. However, I don't agree with all that you said.
I don't see this board headed toward the slow attrophic death that milwaukeescuba seems to be suffering. I think this board is growing more exciting all the time. You have people from all over the state (and a few who just dive here but live elsewhere) discussing all segments of diving. The conversations that seem tied to 'dir' like long hoses, backplates, and theories on deco are really just a small section of what is discussed, and do represent a fair part of the diving done on both of Wisconsin's shores. Lots of the diving here seems to be great lakes wreck diving, and lots of those wrecks are deep, or require special tools for penetration.
You don't see the bickering, namecalling, and philosophical arguments that so frequently arise when DIR-vs-everyone else comes up.

That being said, I do agree with you in that the training agencies are responding to market demands for 'quicker, cheaper, easier'. But is that justification for the weekend certification, or just pandering to the lazy to make more money? We don't make drivers license tests quicker and easier for those unable...
I don't know what the full reasons are for the quick c-card, and am not expert enough to say, but seeing some of the divers who are certified for DM or wreck, or ice diving and their skill level, I question how they got to that certification level.

[Colin]

Scubert, a little off topic, but here goes:
It really comes down to the instructor, and how well they follow the standards of their particular training agency.

As a PADI Course Director (Instructor Trainer), I can tell you the materials and teaching methods for recreational diving have dramatically been improved, even over the past 5 years. Multi-media, including videos and now DVD and CD-ROMS have made the instructor's job a lot easier, if they are used as intended, and the student's grasp of the concepts better. The real "test" is how the student divers APPLY the principles learned in the classroom and pool to open water dives.
The ideas of schedules and logistics are secondary to that idea. Many of today's scuba courses are "performance based" rather than "time based", meaning if the student has mastery of the material, why beat a dead horse, so to speak. That of course, raises a bigger question of what is mastery? This is where the instructor's judgement comes into play, to refer back to my original comment here.
I've had students referred to me from some local instructors who have never heard of some of the skills taught in the open water class, or whose original instructor never explained WHY a particular skill was important. To me, this is just having the student perform "tricks" rather than SKILLS.

So...back to the discussion on computers....

Colin.

[FreediveWI]

Sorry Tom, but I really don't see this site going the same way as the Milwaukee scuba site. Have you seen the sister site to this one? MNscuba.com has a lot greater diversity on it than this site. THey have even more discussions than the DIR/stroke ones. THey have a whole group of mixed gas rebreather divers up there that discuss everything good and bad about it- that's something that Wisconsin is WAY behind in. THey even have a freediving section to their board. ;D

They also have a group of shops that offer way more than any Wisconsin shop. Sure everyone offers the latest trip down south, but they also have shops up there running live aboards to the Arctic Circle! They have plenty of tec trips that they advertise and discuss. There are open discussions, and arguments, about the differences in dive palnning and bailouts- something that this thread was originally meant to cover.

People on that forum don't always get along, but is hasn't been driven into the ground either. People should be allowed to discuss what gear they like, where they dive, who has the best price on air fills and which shop/ boat/ instructor gave them the best service. That's the wonderful part of the internet. 8)

You don't have to agree with everything you read or every idea that someone else posts. The idea is to share information.

The original intent of this post was to talk about proper dive planning. When it comes to tec diving, this is the "advanced section, after all, I think that a lot more has to go into it than just strapping a $1,000 computer on your wrist and having at it.

There are plenty of divers out there who have strapped on a computer and dove to 200+ on a single tank, ran low/out of air, and had to share air with a bunch of other divers on the way up. They then go around and beat their chest like their a tec diver. Their not. In tec diving we call that "genepool math" and there is a Darwin award waiting for them with their name on it. And yes, I HAVE had to rescue more than one of them.

Proper dive planning starts with knowing what your gas consumption is, while swimming, at rest, dragging stages, in a flooded suit. This is a vital piece of information for proper deep dive planning. You would be amazed at how many scuba instructors don't know how to do this- it was required in my basic scuba class and I am thankful that it was.

When it comes to tec diving there are many good programs out there. NAUI and GUE are two of the best. When it comes to these programs you know that your going to get a quality instructor because they have raised their standards so high.

The PADI program isn't too bad, but they still make you do this deep air dives which I don't agree with and have talked to them about- not that it did any good. IANTD and TDI are all over the place. There are TDI instuctors that I wouldn't allow to fill my tanks and there are others that I would gladly trust my life to.

You don't have to agree with anything I said, but if you have a better plan and I would like to listen to it.
I haven't always been a DIR diver. I was driven there by having to many experiences diving with others who also weren't DIR and sent me looking for a better way. IF you have worked out a better system, or know of someone who has, I am all ears- that's what this board is for, sharing information.

Jon

[jasondbaker]

Jon, I couldn't have said it better. The forum provides a place where people can exchange and debate ideas. We may not always agree with the ideas but at the end of the day everyone learns and haves fun.

I am not too concerned about the "state of the industry". I know at least a dozen divers who have been certified over the past three years that all have very solid skills. They were freshly minted through the various agencies and then mentored by more experienced local divers. I have to believe that in the "old days" there were good divers and bad divers.

What is the difference between strapping a computer on your wrist or generating the tables on your home computer? Either way you have a computer crunching the numbers for you. The computer is just a tool. I think the real question is how do you plan the dive using the tools you have available. If you strap some gas on your back and a computer on your wrist, jump in the water and shout geronimo, you may receive a call from Darwin someday.

[Deep Blue]

Jason,

I do agree with Colin, in many cases, training is better today than it has been in years past. An example is the weekend class structure. I have taught the 3 week evening classes as well as the weekend classes. I find that I can get much better results in the weekend classes. There are a number of reasons that this is true. Students are more focused, tend not to miss as many classes due to outside committments, and actually spend MORE time in the water as opposed to a more traditional class structure.

The biggest factor in graduating a quality student isn't as much the agency as it is the instructor. You need to find an instructor that has the experience and teaching philosophy that you are comfortable with. I personally will not graduate a student that I would not allow my wife to dive with. Also, just to let you know, I have had students that were not ready at the end of a class, they are allowed to come back and keep working with us until they can successfully complete the class.

As we move forward, the guiding philosophy of Deep Blue will always be "safety first" and then "have fun". A perfect example of our sales philosophy is demonstrated by the number of backplates that we sell. There are lots of different BC's that we could sell, and in 2 years, upgrade to a new one, and in 2 years upgrade to a new one. Once I sell a backplate, my customer has probably the last BC they will ever need. I don't see that as a lost sale, as I truly believe that since they are more comfortable and efficient in the water, they will be diving more and in the end purchase lots of equipment, just not the same thing over and over.

Now, off of my soap box and back to the topic at hand. I think there is a BIG difference between using a computer to PLAN your dive and strapping a computer on your wrist to CONTROL your dive. As you stated, a computer is a tool, and it is critical that you choose the correct tool for the job. The major difference is the midset. In the first situation, you are conciously making decisions before you get into the water. You have the control, depending on the software, you can reshape your profile, change your bottom time, change your depth, change your decompression settings etc. You can do this until you get a profile that is acceptable with regard to exposure as well as risk/reward. In the second situation, you are reacting to what the computer tells you only. The computer is controlling your dive. If you don't have an overhead, this may not be a critical difference, but if you need decompression information to get out of the water safely, it is a critical difference.

I am not saying that there is no appropriate task for a multigas computer, I just can't think of one for the diving that we do up here. Also, per the question earlier regarding whether or not I would sell a mixed gas computer to someone that walked in off of the street, my feeling is that one of the things of value that a dive store vs the internet brings to the table is that we can councel our customers and give them advice on what computer is the most appropriate for them.

[Omicron]

Deep Blue,

I almost wish that I had taken my original training through you I wish that I would have had someone pointing me in the right direction on gear the first time around...instead of having purchased some very expensive recreational gear, I could be diving some quality gear.

It's hard when you are starting out and you don't know any better...