User Guide and decompression information

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@Zef

What we believe and what we think Suunto has in mind is really not relevant. I cannot know for sure but I do not believe Suunto has downgraded anything in regard on how their dive computers display decompression obligations. I believe this because I had other discussions with Suunto regarding the (lack of) functionality in their diving instruments. Suunto is not a company which changes stuff just because it makes their computers more safe to use and easier to use. I have that black on white. Furthermore you might recall I am diving with a DX. I will leave that to you to read through the spec's for this dive computer. However I can share with you not even the DX can do any deco dive planning via the build-in dive planner tool. Such dives has to be planned from DM5 software. So when you are stating other Suunto dive computers can do simulated deco dives in the dive planner tool, then please document this. I would like to see an extract from the UG where this functionality is explained.

I welcome your thoughts and your contributions. But at the end of the day it is Suunto who has to come forward and explain why they believe the lack of detailed information regarding Ceiling, Floor, Ceiling Range and Decompression Range is sufficient. You might be right. Suunto might have down graded the decompression information (I still do not believe that) but Suunto should then just simply make a statement regarding this. If this happens to be so I can for sure just advice divers to avoid the dive computers models in question and (1) choose another brand or (2) just use tables.

I hope Suunto High Level Support is back to work tomorrow Monday. Not that I am expecting them to answer me already tomorrow. I waited several weeks already. I will share the thoughts and answers from Suunto once available.

Cheers,
Morten
 
@Bastianhund

I dive an Eon Steel and the user guide has very little about the deco apart from telling you that if you break teh ceiling for more than 3mins it'll lock you out. I posted the link below for Freewillow in a previous post which explains how RGBM for Suunto's works including more detail on ceilings and floor etc

http://ns.suunto.com/pdf/Suunto_Dive_Fused_RGBM_brochure_EN.pdf

You'll be correct about no plannign on the PDC. teh most teh Eon will allow you on its planner is gas mix and depth to give you a max NDL. A bit pointless on a multigas flagship computer - something I've put forward to Suunto (as not always do I have my laptop to run DM5)
 
@Diving Dubai

Thanks for the link. I have never seen this paper before. Interesting reading. I have (quickly) reviewed the text and I am now slightly more positive towards the Suunto Fused RGBM than before.......but that's another story. Unfortunately this information is not a part of the standard User Guides. Not sure it should ever be. As a minimum Suunto should add this link to their UG's and make their customers aware of this additional information. Just my personal opinion. I still want Suunto to add model-specific information related to how to interpret the decompression information in the display.

Cheers,
Morten
 
@Bastianhund. Presently I have an OSTC Sport from heinrichs Weikamp .

This is an European tec computor. It has a 96 pages instruction for use. At NO TIME, does the instruction for use describe how to make a decompression dive. However it has a "planning" function that is well described were you can plan your dive as you want. It is a quite sophisticated thing where you can change/adapt quite a few items: selection of algorythm, safety factors, GF low/high on Buhlmann, depth of your shallowest deco stop etc, of course one can change gas mix under water for deco up to 100% O2. I am on a french speaking forum that has 1777 posts :yeahbaby:on this model alone. A lot of B.S. in them but this is how divers learn to use it, by sharing experiences. :cuddles:

My guess is that ANY computor should/will refrain from giving recommendations on how to decompress at the end of a dive. This would be way too dangerous, liabilitywise.

As dicussed earlier, deco dive is something that can turn bad. People need to be SERIOUSLY trained in order to be able to do it with some level of security. It is for good reasons that most recreational computor manufacturors tell you NOT to enter into deco. Lawyers are checking the instruction for use before print. :laughrant:
 
@Bastianhund

The Vyper, Vyper 2, and Vyper Air all have "SimDive" function built in. I am not saying one should use this function to plan decompression dives but one can certainly simulate a dive where the NDL is surpassed and then see the resultant deco obligation generated by the computer. This feature is described on page 86-87 of the Vyper Air manual, and pages 90-92 of the Vyper manual.

In essence the Simdive feature is a tool for the diver to use to become more familiar with their computer, plan dives with, or use for educational demonstration purposes. The dive time advances 1 minute after each 15 seconds. One can descend to what ever depth they desire and let the clock run for however long they want to see how the dive will play out. It will indicate decompression zones, stops, etc, just as the computer would during an actual dive.

-Zef
 
@Freewillow

I understand what you mean when you claim no dive computer user guide should teach divers how to do decompression diving. This tasks should be handled by dive instructors. To carry out deco dives safely requires a lot more than the ability to follow the instructions of the dive computer.

But when a dive computer is advertised as "Full technical" (as my Suunto DX) and will display the necessary decompression obligations to the diver, then it would only be fair to let the diver know how to interpret this information. Whether or not the diver is willing to take the risk and dive beyond the NDL will never be the problem of e.g. Suunto. Just read all the warnings which is listed in the Suunto UG's. The Suunto UG's are packed with statements which releases Suunto from any liability......which I can understand.

You are guessing wrongly. Almost all dive computers are providing some kind of a decompression schedule for the diver once the NDL has been exceeded. The diver should know that and the diver should familiarise himself/herself with the decompression strategy provided by the dive computer in use. @Diving Dubai has provided detailed information which outlines the current strategy applied by Suunto. Whether or not you find this strategy safe to use will highly depend on your actual training.......in decompression diving.

My DX has a pretty high price tag. I do not want to learn how to use it by asking around on the internet. I expect the manufacturer to provide adequate information.

/Morten
 
@Freewillow


You are guessing wrongly. Almost all dive computers are providing some kind of a decompression schedule for the diver once the NDL has been exceeded.
/Morten

Then I did not express myself correctly. :facepalm: I meant that most INSTRUCTION FOR USE MANUALS will not give you a precise deco schedule. It will only tell you where to make your first stop and for how many minutes. As far as I have seen on my computors instructions for use, this is it. But I have not read nor used many computors in my life. :happywave:
 
I had a read of the novo zoop manual to see what the fuss was about. It still has ceiling and ascent time. What more do you need? The floor feature isn't useful (to me at least). My shearwater doesn't show that.

Earlier in this thread a point was made about the psychological Impact of being in deco. I think this should not be underestimated. Unlike a physical barrier the commitment is in your head. You need to be sure you can hold back the urge to surface no matter what. Cold, need to pee, boredom - whatever it is you are committed. This is a reason to build up gradually.
 
Earlier in this thread a point was made about the psychological Impact of being in deco. I think this should not be underestimated. Unlike a physical barrier the commitment is in your head. You need to be sure you can hold back the urge to surface no matter what. Cold, need to pee, boredom - whatever it is you are committed. This is a reason to build up gradually.

Thank you Ken, finally one diver that understands what I was trying to say :thumb:
 
Reply from Suunto Customer Support pasted in below. Enjoy the reading (FYI: No updated User Guide/Manual was attached to the original mail I received)

"We sincerely apologize for the delay in getting back to you.

We have forwarded your concern to our developers to improve the manual and attached herewith is the updated one.

We understand that this information is very important to you as a diver and as an instructor to get vital information in understanding how to safeguard divers. Let us try to explain the best we can and please do not hesitate to respond to this email if we miss some details.

Instrumentation for diving:

1. Access to vital information in order avoid decompression sickness:
- Depth
- Time

2. Knowing how much air you have left:
- Cylinder pressure

3. Additional useful information includes e.g.,
- water temperature
-direction

Air consists of 79% nitrogen (N2) and 21% oxygen (O2). When breathing compressed air underwater, N2 dissolves into body tissues as the dive time increases. In order to avoid decompression sickness, divers must follow dive tables or use dive computers that calculate the “no deco time.” The higher the temperature, the less dissolved gas a liquid can hold. This is also the reason why most dive computers have an ascent speed indicator. In addition, the N2 interferes with signal transmission through CNS causing intoxicating effects (“Martini’s Law”). Under pressure, O2 becomes toxic to humans (this primarily only concerns Nitrox and tech divers). It can cause:

a. pulmonary oxygen toxicity (lengthy exposure to PO2 greater than 0.5bar)
b. CNS toxicity (PO2 higher than 1.6 bar)

In tec diving Helium is used in the breathing gas to substitute O2 to reduce the PO2 (oxygen toxicity)and N2 to avoid narcosis. Tec divers also use rich O2 switch gases to accelerate decompression -> the deco calculations become more complex and risk of fatal errors increase if calculations were only done manually.

These dive computers has functionality to protect diver having the decompression sickness. Part of the protection is the no fly time, automatically have 48H in which you cannot use any other dive mode and is locked down in free dive mode if ascent speed violation more than 10m/min. Other safety features are the safety stops, deep stops, and decompression stops which is variable depending on calculations to dive time, depth, temperature etc.

Please refer to the link below for more information explained by Dr. Wienke on his short videos pertaining to more in-depth explanations about these dive computers and its algorithm.

Suunto

We hope that this info helps and please do not hesitate to respond to this email if you have more questions and clarifications.


Sincerely,
Val
Suunto Customer Support Team"
 
https://www.shearwater.com/products/swift/

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