Teaching Computers in OW class vs tables

[MikeFerrara]

Other reasons that I wouldn't teach only computers.

If you look at multiple tables the first thing that you'll notice is the huge verience in NDL's. In some cases it can be up to 40% or so.

If you go beyond that and look at the decompression scheduled given for dives beyond the no-stop limits the differences can really be enlightening.

If you play with some decompression software you'll see that by changing user settable parms you can modify a scedule by maybe hundreds of percent.

The point is that the, down to the foot and the minute precision that divers think they are getting with a computer is total BS. General dive habits are far more important that the exact NDL that you use.

 

[jviehe]

If you look at the DAN stats though, most injuries are caused by rapid ascent or medical problem, in just about 80% of the cases. Of the minimal number of hits, there are very few "undeserved" hits, and Im not sure diving a table wouldve helped in these cases, since the computer and the tables are based on the same original models for the most part, as I understand it.

The DAN stats dont reflect that computer divers are more likely to get bent, just that diver who get bent are most likely using a computer. Which is why Id like to see the stats he has.

 

[GDI]

Which stats, and was it statistically significant?

There has been a ongoing project using the resources of DAN, DSAT, USN, RN and DRDC. Some computer vendor/manufacturers support this program. There is also the accident stats. My comment on stats comes from and agrees somewhat with what you are saying (DAN, DRDC, USN and DSAT) Other then just fast ascents or medical conditions. Many divers using computers push the computer's limits and are diving deeper than their training and experience are prepared for. DCI is not just a result of deep diving there are many variables and computers cannot be fully to blame. I agree that tables would not be any different in a rapid ascent possibly causing DCI. I also don't fault retailers for pushing computers.

I believe that computers and tables need to be instructed to work in tandum with each other. Newer computers are having updated programs installed. More bells and whistles as well. The technology is there and we need to learn to use it and not rely solely on it. Tables are also evolving as science works to learn more regarding DCI
I teach both with heavy understanding on the tables and the use of computers as a monitoring device. I always dive with two computers and in line with tables. I also set my bezeled watch to track BT. Divers didn't use or have computers when I started diving and the knowledge of DCI wasn't what it is today

 

[okinawascuba]

So many people are worried about computer failures, but personally, I'm more worried about a regulator failure. What happens if your watch fails or your bottom timer fails? Seems like the same issues arise there.

In any event, I do use a computer (non-integrated), but I also still carry my depth/pressure gauge and my dive watch. I am covered both ways. I must admit, though, that I mainly wear the watch because I was so proud to finally own a dive watch (a real one, Seiko, not Timex) that I can't bear the thought of not wearing for its primary purpose.

 

[GDI]

So many people are worried about computer failures, but personally, I'm more worried about a regulator failure. What happens if your watch fails or your bottom timer fails? Seems like the same issues arise there.

In any event, I do use a computer (non-integrated), but I also still carry my depth/pressure gauge and my dive watch. I am covered both ways. I must admit, though, that I mainly wear the watch because I was so proud to finally own a dive watch (a real one, Seiko, not Timex) that I can't bear the thought of not wearing for its primary purpose.

Computers don't really have a high rate of failure. The weak link in the whole system is the divers failure to trully understand the information and purpose and use it correctly, tables or computers

 

[jviehe]

Computers don't really have a high rate of failure. The weak link in the whole system is the divers failure to trully understand the information and purpose and use it correctly, tables or computers

You led to a good point too, which is that divers typically dive computers to the limit, becuase it is more accurate. Since most divers dont do square profiles and round conservatively a lot with tables, their NDL is very conservative in reality compared to a computer. As with any training, I think you just have to stress the benefits and risks of any diving technique, be it tables or computers or discover trimix.

 

[MikeFerrara]

You led to a good point too, which is that divers typically dive computers to the limit, becuase it is more accurate. Since most divers dont do square profiles and round conservatively a lot with tables, their NDL is very conservative in reality compared to a computer. As with any training, I think you just have to stress the benefits and risks of any diving technique, be it tables or computers or discover trimix.

Good point. A diver who is using a computer to get closer to a "NDL" is putting themself in a situation where ascent technique and overall dive habits are that much more critical.

In this case some how believeing that an NDL is some kind of a hard line where you're safe on one side and in trouble on the other can be a bad thing.

I don't view the NDL's on tables or computers as being conservative or safe as many people seem to. Look at the difference from one table to the next...DSAT 100 ft NDL = 20 minutes and buhlman = 17 (I think). That's a 15% difference.

Pump either one through dplan (Buhlman with gradient factors) and niether is a no-stop dive.

The same 20 minute dive on vplanner (vpm A) set with middle of the road conservatism requires a 1 minute stop at 30 ft and a 7 minute stop at 20 ft. VPM B I believe added time to the shallow stops so there would probably be a little more time required.

The point is that a dive to the NDL of most computers or tables is not something that I would do as a no-stop dive and I sure don't view it as conservative.

 

[jpence151]

My response is that ideally we will do away with tables eventually and people can learn to use them as a backup if they wish, much as most divers do once they get out of class. Additionaly, one thing i think being missed is how able some is to follow tables and do math in a stressful situtation. I think computer help alleviate this posssible user error.[/QUOTE]


I you believe what you say then you would agree that Schools should teach using a calculator in the first grade and forget about teaching the fundamentals... This is not good, what if the computer stopped working in the middle of a dive (Dead Battery, or other reason), you just lost a good day to dive. If you learn the tables then use the computer for convience then you still have the tables.....

If your watch or bottom timer fail, you take the hi end time for the dive and stay out a little longer, but you don't lose the whole day....

you always have a buddy with same equiptment in case of failures right, but then again if you go with computers in class and not training then you are also making the sport much more costly... Learn the tables it's not that difficult....

 

[jviehe]

Yes, thats true, but computers seldom fail, so why prepare for something that almost never happens? I think the bigger worry would be user error as a result of not being able to follow tables in a stressful situation. If you are really concerned, get a backup computer.

 

[mstudley]

computers seldom fail

yea really... I mean, i've been using this thing here for ab0*&#9618;rΪÈ<âhMÍËw.ò±<GÛ<Wz©ÒêÅØÑ)©«.Fë}39|_[¨zßÑUËÏOÿ(îù:À+ð¨±ËÏ·j5¶[¢Äh9¸&#9618;cÇÝ!dâsqNåÃ4
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