Do Oceanic Computers have a bad reputation?

[GreenDiverDown]

pasley,

Good post! Your points are good ones worthy of consideration.

But...

There is some wierdness going on with your numbers...or...I'm having trouble figuring out how the Data Max could be blamed for your troubles. ( I understand that YOU aren't blaming the Data Max.)

Here are some more numbers...

If you stayed "in the green" on the ascent rate indicator bar graph it would have taken you almost 3 minutes to surface. (30-40 feet per second.) Then you would have done a safety stop at 15 feet for three minutes. That is a total of 6 minutes to surface.

Subtract that 6 minutes from your " Dive time surface to surface 19 minutes" and you get a bottom time at 107 feet of 13 minutes.

A PADI table shows the NDL for 110 feet to be 16 minutes.

The Data Max plan mode shows the NDL for 110 feet to be 16 minutes.

The Suunto Vytec plan mode (RGB 100) shows the NDL for 110 feet to be 13 minutes.

So...

You would have been within the NDL for a table and also within the NDL for the Suunto model.

I'm not sure why you did a stop at 60 feet. The Data Max only has ceilings for 40, 30 and 20 feet.

I"m not sure why you did stops at 40 and 30 feet. You shouldn't have gone into the red if your bottom time was only 13 minutes. There shouldn't have been any ceiling requirements at all. (For those of you that don't have a Data Max, it has a red zone in the Tissue Loading Bar Graph that is sudivided into required stops...or ceilings. The longer that you exceed the NDL the further into the red zone it goes... adding required stops at 20 then 30 and finally 40 feet.)

Wierd!

Maybe something else was going on. Was this the first dive of the day? Did you do some more dives after this one? Did you fly too soon?

But you're right. You can dial in more conservative measures with the Suunto. For instance, if you crank up the diver profile to P2 you get an NDL for 110 feet of only 9 minutes.

But then again, you can dive the Data Max and stay "in the green"
or stay earlier "in the green" and the end result is the same...a more conservative profile. Of course, this assumes that you follow all of the other rules, too. (I'm not saying that you didn't follow the rules, BTW.)

Bottom line...you can make the Oceanics as conservative as you want.

SA

 

[JeffMandell]

pasley once bubbled...



I followed the computer. Depth 107 FSW, Dive time surface to surface 19 minutes. Did safety stop at 60, 40, 30 and 15 feet. Remained at each depth until computer showed nitrogen load in the green. Ascended in the green on the accent speed indicator.

Next I dove the decompression chamber for a total of 3 dives at 2 hours each.

That is when I found out that the tables on this brand of computer are very liberal.

Was it the computers fault? I can't say it was. Perhaps it was just one of those things.


Well, glad you're ok.
That said, I was thinking when I started this thread about whether the negatives about Oceaninc that I'd read on this board are anecdotal, so I'm hesitant to write off Oceanic based, even though I understand why you did.
I'm not putting my head in the sand, but, FWIW, I read recently that some two thirds of all DCS cases occur without any violation of DCS parameters, regardless of brand.
What I do take from this discussion is it might make sense to back off and consider the last green bar on the computer to be yellow, thus diving more cautiously.
The posts here have been very interesting and helpful, even if the issue doesn't see to be quite settled.
Oh, and yes, the big numbers on the Oceanic display are nice for my middle-aged eyes, so I'd trade that for its lesser download software if there's no statistical loss of safety with it compared to other computers.

 

[newdiverAZ]

when I plug that profile into Gap software it kicks back deco stops

 

[newdiverAZ]

One other question about that profile? Why didn't you stay at 10' longer? With a sac of .6 you only used 33.5 cu. ft of gas assuming an al 80. Why not stay down longer @ 10' and offgas and work on bouyancy or check the sites. Also where you doing strenous exercise once on the surface. I like Uncle Pug's method of enjoying the World's largest waterbed. I feel this hit can not be blamed on a computer at all. I feel for you, but you could have done several things differently to help this dive.

 

[Karen Cleveland]

newdiverAZ once bubbled...
I feel for you, but you could have done several things differently to help this dive.

I might have missed something but I can't find enough info in Pasley's post to make any evaluation on what he might have done differently to help the dive. "Undeserved" hit translates to me as , "we really have no idea what caused it" of course you can speculate and replay the details leading up to it all day long.

Karen

 

[newdiverAZ]

I seem to see where I was asking questions about his profile. I don't think you can just blame that hit on a computer, there are several things even I as a newer diver would have done, instead of just riding the computer, and I also dive with a computer, but don't depend on it.

 

[newdiverAZ]

and I would think riding an NDL to the limit and riding a computer to a limit and following a "theoretical model" to a limit is not a good idea. I may be wrong. But don't think this is reason to blame a computer, and especially any 1 brand of computer.

Karen Cleveland once bubbled...


I might have missed something but I can't find enough info in Pasley's post to make any evaluation on what he might have done differently to help the dive. "Undeserved" hit translates to me as , "we really have no idea what caused it" of course you can speculate and replay the details leading up to it all day long.

Karen

 

[Karen Cleveland]

newdiverAZ once bubbled...
and I would think riding an NDL to the limit and riding a computer to a limit and following a "theoretical model" to a limit is not a good idea. I may be wrong. But don't think this is reason to blame a computer, and especially any 1 brand of computer.

You're right....I was looking at it from a different angle. By that I mean dehydration, lack of sleep, exertion, anxiety...blah, blah blah. My computer has been set to guage mode for too long.

Karen

 

[MJillKDives]

This quote regarding the Versa Pro comes from a review on divernet.com. After reading it I decided on a different computer:

"Page seven of this [the instruction manual] states: The decompression model used by an Oceanic dive computer is based on the no-decompression multi-level repetitive dive schedules successfully tested by Dr Ray Rogers and Dr Michael Powell. These tests did not include dives deeper than 90 feet (27m) or decompression (stop) dives. Decompression-stop dives are the type of dives I commonly do, and I took the Versa Pro on a series of 12 such dives (many repetitive) alongside a Cressi Archimede and a Suunto Vytec.

Only once did the Oceanic momentarily show me entering deco-mode, though the other two had me into deco-mode on nearly every dive.

Not only that, but the discrepancy between the amount of no-stop time remaining on the Oceanic Versa and the deco-stops demanded by the other two was alarming."

You can read the entire review by going to Divernet.com and clicking on "Equipment" and "Diver Tests."

 

[pasley]

Thanks for all the input from everyone. Here is some additional information.

This was my only dive of the day. I had not dived for 2 days before this. I got a message in the afternoon inviting me to dive. Normally when I dive, I really watch the water the day before an push it, and the day of the dive, no coffee or coke, just lots of water to ensure proper hydration (something I should do everyday, even when I am not diving, but most of us don't). So I had not spent the previous day watching to ensure I drank all the water we should drink everyday. In short, I had coffee for breakfast (just a little, about 4 cups) and a coke for lunch and maybe a glass or two of water.

I stopped deep because I went quickly from depth to 60 feet to get more air time as the computer was telling me I had 2 minutes of air left. I knew I would get more at a shallower depth. The computer did not go into the red on anything, but was well into the amber on nitrogen loading.

I should have stayed at 15 feet and drained the tank dry. That was a mistake as I surfaced with 400 psi in the tank. Too much air. But my computer was not indicating a mandatory stop or wait at that depth.

The other issues are I can only relate what I remember looking at. That is a good argument for a downloadable computer. Ask yourself these two questions: 1. On the average dive, how often do you check the gages? 2. How many of those times can you recall post dive?

This was my 12 dive and was only 2 months after certification. I would definitely handle the situation differently today. At the time I was 155 lbs, 72" BP 101/60 (today 146 lbs, still 72" and BP 98/58 (with the occasional 85/50 after a good run, just to scare the nurse). At the time I was an air hog. Today my SAC runs usally runs between .43 and .47 depending upon dive conditions and currents.

Bottom line is both DAN and my dive doctor agree my profile was such that I should not have been bent. But I was, and with nerve damage. Stuff happens. Sometimes even if you do everything right, you still get bent. Do I blame DATAMAX? No. But given my age (now 49) and history of being bent it is not the right computer for me. I do think DATAMAX computer is well designed for the middle to older diver, but uses too liberal a table for that market.

I just wanted to point out that a major consideratin for buying a dive computer is the model the computer uses to base its computations on. Select the model that is right for you.

I also talked myself out of the downloadable feature on my first computer as a luxury. I now view a downloadable computer as more of a self improvement item. It helps me study my dive profile and improve it. It is also a record for the medical folks if I get bent again.