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John Firstly, your last point: >do you think that we are still that far >apart? You asked a question, I provided an answer with points to consider. I done recall suggesting one was better than the other. In practice both have benefits and drawbacks. What they have in common is that they provide a guide to the deco required. You dive with what you feel comfortable. Go and re-read your question and my responses. >So the computer on your wrist would have to: >1.Have an identical algorithm to that of the desktop program No. >2.Adjust for deep stops (if that's a consideration) No, if one subscribes the Helium is the prince of gasses and Buhlmann got it wrong camp, then what is required is a "correct" algorithm, customisable for individuals. >3.Provide deco information in the event that you violate the given depth >ceiling (carrying backup recompression tables here would obviate this need?) From a design and legal point of view, I could not see this happening. My original point is that this is a difference between a table and a computer. Tables still show you what you should have done, computers do not. >4.Record data and produce info based on the depth range you are concerned >with (e.g. my air computer goes to 99m, so adequate for air dives). Yours does, others do not. My point was that this is a difference. >5.Be able to operate at a conservatism level set by the operator. Absolutely. >Given that there is (probably) not an algorithm published that adjusts >shallow stops given the addition of deep stops, Agreed. > and that some agencies >forbid in-water recompression I will do what I consider to be best for me in the specific circumstances I find myself in rather than blindly following the advice of an agency. David Shimell Project Manager, Sequent Computer Systems Ltd., Sandton, South Africa. Email: shimell@se*.co* <mailto:shimell@se*.co*> -----Original Message----- From: Taylor, John [SMTP:john.taylor@cs*.co*.uk*] Sent: Friday, May 14, 1999 11:48 AM To: techdiver@aquanaut.com Subject: RE: Abyss Explorer Nitrox David, So the computer on your wrist would have to: 1.Have an identical algorithm to that of the desktop program 2.Adjust for deep stops (if that's a consideration) 3.Provide deco information in the event that you violate the given depth ceiling (carrying backup recompression tables here would obviate this need?) 4.Record data and produce info based on the depth range you are concerned with (e.g. my air computer goes to 99m, so adequate for air dives). 5.Be able to operate at a conservatism level set by the operator. Given that there is (probably) not an algorithm published that adjusts shallow stops given the addition of deep stops, and that some agencies forbid in-water recompression, do you think that we are still that far apart? Best Regards, JT -- John Taylor, Marketing and Trading Systems, IT Development Credit Suisse Financial Products (Hong Kong) Ltd, 13F, Tower 3, Exchange Square, Central, Hong Kong Office: +852 2101 6927, Fax: +852 2101 7698, Mobile: +852 9031 6395, email: john.taylor@cs*.co*.uk* [private e-mail: live4diving@ho*.co*] > -----Original Message----- > From: Shimell, David (shimell) [SMTP:shimell@se*.co*] > Sent: Friday, May 14, 1999 4:32 PM > To: Taylor, John; techdiver@aquanaut.com > Subject: RE: Abyss Explorer Nitrox > > John > > >What is the difference between following a deco schedule produced from a > set > >of (computer-generated) tables, and following a deco schedule produced by > a > >computer on your wrist? (Apart from algorithm differences and that the > >computer produces a schedule for the dive you actually did) > > Consider the following: > > * Most dive computers have built in safety as do some desk top deco > programs. With some desk top deco programs one can switch off the > safeties, > e.g. the Abyss desk top deco program comes out of box with an assumption > that > the diver will ascent to 540m after the dive. Thus the table produced > will > keep the diver in-water on the last stop longer than if the diver were not > to > ascent to 540m. This post dive altitude adjustment can be set to zero. > > * If one inserts deep stops with a computer, the computer will add > time > to the deco as it considers some of your tissues to be on gassing to the > extent that additional time at the shallower stops is required. From > posts > of some of the WKPP people, it is their practice to shorten the shallow > stops > not lengthen them after applying deep stops to the dive. > > * If you skip all or part of a stop on a computer it typically goes > into violation mode and does not provide deco information. Tables are > still > there and available as your guide to the deco required. > > * Some computers only operate within certain depths, deco depths, etc > Tables do not have this limitation. > > * Some computers penalise you for the low ambient temperatures, tables > do not. > > David Shimell > Project Manager, Sequent Computer Systems Ltd., Sandton, South Africa. > Email: shimell@se*.co* <mailto:shimell@se*.co*> -- Send mail for the `techdiver' mailing list to `techdiver@aquanaut.com'. Send subscribe/unsubscribe requests to `techdiver-request@aquanaut.com'. -- Send mail for the `techdiver' mailing list to `techdiver@aquanaut.com'. Send subscribe/unsubscribe requests to `techdiver-request@aquanaut.com'.
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