Do decompression divers use computers?

[Tortuga68]

Well I'll chuck in my 2 bar...

I use my Suunto Vyper in gauge mode, with a run time plus bail out on a slate, and an older model Citizen Aqualand for backup/deco stops (for the second hand)

Unfortunately the Vyper will then lock me out, so if I'm planning on using it for rec. dives in the next day or two I'll borrow a Uwatec bottom timer instead (if I'm diving in PG where a loaner is available from friends)

 

[Bismark]

I use a very nice Mac book pro running Fusion so I can run Decoplanner........;-)

 

[JeffG]

I use a very nice Mac book pro running Fusion so I can run Decoplanner........;-)

stroke alert

 

[Bismark]

stroke alert

Takes one to know one.............. I have some PC's too if that makes you feel any better you heretic.............

 

[Bismark]

Once I put Vista on them, you should just be able to log in to them from your phone anywhere...........like the other 5 billion computer users in the world................

hijack over......... but then you probably knew that if you had some six year old hack the security on my XP and were reading my key Strokes................

 

[Chatterton]

jackie,

I posed the question to Dick Vann the head of research at DAN. Below is his answer?

John,

A good resource for anyone interested in the deep stops is the proceedings of the Deep Stops Workshop held in Salt Lake City at the UHMS meeting last June. It can be ordered from UHMS.

The conclusion of the workshop was that the VGE data were inconclusive concerning the effects of deep stops because some studies showed deep stops helped and some showed they hurt.

The more important question is how do deep stops affect DCS risk and there was very little data that addressed that question but all available data indicated that deep stops were harmful. The Navy study was unequivocal in showing poor results, but there is enough wiggle room to say that ÅÎaybe the Navy didnÃÕ test exactly the right kind of ÁÅeep stops? There were a few other trials with DCS but with too few dives to draw strong conclusions.

There was a problem in defining what was a deep stop still unresolved.

The training agency presentations were strictly infomercials and of no value in answering the question.

So the bottom line is the jury is still out but the case for deep stops does not look good.

Best regards,

Dick



From: John Chatterton [mailto:jc@johnchatterton.com]
Sent: Monday, January 26, 2009 8:39 AM
To: Vann, Richard; Denoble, Petar
Subject: More questions

Gentlemen,

A question has come up on an internet forum with regards to decompression, apparently something you know about.

I have never been a strong supporter of deep stops. Regardless of small variations, it seems to me that the Pyle, WKPP, or Micro Bubble approach is flawed? At the DAN Tek Conference, I had the chance to talk with Richard Pyle who commented that they simply donÃÕ work. At the same time, there are decompression software programs that use the concept?

What is the latest in research to either support or refute the science behind deep stops? Bottom line, what do you guys think?

I hope all is well with you both.

Cheers

JC

Will you supply references to this new research?

Thanks,

Jackie

 

[Chatterton]

I originally ordered this computer from Abyss, through Chris Parrott and Joel Silverstein (another story). After a two year wait, while they developed the unit, I finally got one, right before Abyss went out of business. It locked up on my 6th dive. Joel and Chris immediately passed me off to HSE. Over the next two years I had eight of these things. They flooded, locked up, went blank, and otherwise died, all but one in the water on a dive. One came out of the UPS box doing a 748 foot dive??

When one failed, I would send it back and wait, weeks, for the next one. After 8 units, I had no confidence in the computer, or the company. They did not offer to return my money, and I would not sell it to some unsuspecting diver. I threw #8 in the trash. From my experience, bad computer, bad service.

I sympathize with dive equipment manufacturers, and the difficulties they face in making the gear we need. I am not in the habit of going around slamming dive gear that disappoints me, but I think the continued bad performance of this product, speaks for itself.



Cheers

JC

OUCH!

I use this computer. I'd appreciate if you'd expand on your concerns. You mean doesn't work "physically"- like batteries don't last very long, or can't accurately measure the depth/time- or do you mean "mentally" like bad or unsafe or out-of-date-algorithm?

Or maybe your reference is to how it works with CCR and that might not apply to how it works with OC?

Anyway, I only use it as backup to computer generated tables, but the HSE RGBM algorithm does seem to follow the RGBM algorithm from GAP pretty closely.

Thanks in advance for your input.

 

[Chatterton]

Petar Denoble is the #2 research guy at DAN, and works in the field collecting data as well. He was with us on Britannic. He has these very insightful comments to add about Deep Stops:

John.

I would like to add one more point. If there are any effects of deep stops, they are so minuscule that is hard to demonstrate them while other factors like exercise and temperature have effects on outcomes of such magnitude that every diver should take them into account.


Take care,



Petar

 

[battles2a5]

John,

Do you know if their deep stop workshop focused on traditional "pyle" stops or manufactured stops (a la VR3) or were they based on the dual-phase models or modified Buhlmann? Based on the this, do they have any recommendations regarding algorithms, or which configurations (e.g. gradient factors for Buhlmann, bubble nuclei and permeability for VPM, etc.) have proven to be most efficient (or least problematic)?

Thanks!

 

[Tomeck]

I think RGBM is very good for stop decompression.