Dive computers

>>As long as I keep within the safety zone I shouldn't have any problem.<<<


The benefit of a computer is to get you out of trouble when you don't stay
within the safety zone!

Some of us actually do this intentionally, its called deco diving. The Tech,
Wreck, and Cave divers push the limits all the time. There are advanced
computers that are not all that much more expensive than the basics that are
designed to track mixed gasses as well as multiple gasses. They would be the
better bet if you intend to keep diving and get into advanced diving.

John

"gocart" <harlanjs@pacbell.net> wrote in message
news:harlanjs-E06BEB.12072412112005@newsclstr02.news.prodigy.com ...
>
> Seems like everyone agrees that the computer is the way to go and with
> the price of the "basic efficient', according tho the reviews in Scuba
> diver mag, Sherwood Profile down to less than 300 bucks I'm going for it.
> As long as I keep within the safety zone I shouldn't have any problem.
> Thanks,
> Harlan

gocart wrote:
> Seems like everyone agrees that the computer is the way to go and with
> the price of the "basic efficient', according tho the reviews in Scuba
> diver mag, Sherwood Profile down to less than 300 bucks I'm going for it.
> As long as I keep within the safety zone I shouldn't have any problem.
> Thanks,
> Harlan

I would suggest you -
(a) shop around with different models and manufacturers

(b) talk to other divers. See what their experiences are. What they
are happy with/unhappy with.

(3) If you are not Nitrox trained, get one that has nitrox capabilities
anyhow. They are not that more expensive than air only. When I bought
my first computer, the local dive shop guy told me he stocked only
nitrox capable computers. Even though I was not nitrox certified at the
time, if/when I did become nitrox certified, I would not need to buy a
new computer. It turned out to be a wise move to get one that was
nitrox capable. Even if you never get nitrox training, if you ever go
to sell it, you will have a much bigger market than if it were air only.


--
I have never met a liberal street cop.

At the very least, check into a computer that can be used with nitrox.

gocart wrote:
> Seems like everyone agrees that the computer is the way to go and with
> the price of the "basic efficient', according tho the reviews in Scuba
> diver mag, Sherwood Profile down to less than 300 bucks I'm going for it.
> As long as I keep within the safety zone I shouldn't have any problem.
> Thanks,
> Harlan

"Dr Yak" <Dr.Yak@NoSpam.Com> wrote in message
news:jsxdf.13541$4l5.12634@dukeread05...
> At the very least, check into a computer that can be used with nitrox.

The Doc has the right diagnosis.

Air-only computers aren't even useful for leveling the coffee table.

> gocart wrote:
>> Seems like everyone agrees that the computer is the way to go and with
>> the price of the "basic efficient', according tho the reviews in Scuba
>> diver mag, Sherwood Profile down to less than 300 bucks I'm going for it.
>> As long as I keep within the safety zone I shouldn't have any problem.
>> Thanks,
>> Harlan

Dan Bracuk wrote:
> Dennis Willson <giganews@taz-mania.com> pounded away at his keyboard
> resulting in:
> :You may also want to consider a quick release for the console so that
> :you can remove it from the reset of your gear and put it away so it
> :doesn't get banged up or stolen.
>
> I saw someone with one of those. It looked cool so I got one. I no
> longer use it. Maybe it was just mine, or just me, but it seemed to
> loosen itself from time to time.
>
> Come to think about it, the reason I notice that the first guy had it
> is that it loosened up on him.
>
> Dan Bracuk
> If we don't succeed, we run the risk of failure.
>
> ----== Posted via Newsfeeds.Com - Unlimited-Unrestricted-Secure Usenet News==----
> http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+ Newsgroups
> ----= East and West-Coast Server Farms - Total Privacy via Encryption =----

Well mine cannot come "loose" when the system is pressurized. The air
pressure makes it pretty much impossible to disconnect. You have to
purge the air out of the system to disconnect it. I (and no one I know
that uses the same disconnect I do) have never had a problem with it
coming loose even when there isn't any air pressure.

Dennis

Josh Assing wrote:
> You should definately learn the tables...
> A dive computer is handy -- but if hte battery dies, and you haven't done your
> tables.. well; what's OK for next dive?

Hmm, I did a dive yesterday with a maximum depth of 30m and a bottom
time of 38 mins. If my computer failed what's OK for the next dive on
tables?

--
"If a man empties his purse into his head, no man can take it away from
him. An investment in knowledge always pays the best interest." -
Benjamin Franklin

On 2005-11-14 23:53:05 +1300, BarryNL <no@spam.com> said:

> Josh Assing wrote:
>> You should definately learn the tables... A dive computer is handy --
>> but if hte battery dies, and you haven't done your
>> tables.. well; what's OK for next dive?
>
> Hmm, I did a dive yesterday with a maximum depth of 30m and a bottom
> time of 38 mins. If my computer failed what's OK for the next dive on
> tables?

If you're going to do that - just learn a little about deco, and then
you can plan you next dive to your heart's content.

I use BSAC 88 tables as my standard backup, but Buhlmann tables would
be fine too (as well most of the currently available deco software).
Just make sure you know what you're doing before actually getting in
the water...

(I'd get my tables right now, but I'd make too much noise and probably
get shouted at because most of the house is asleep).

"BarryNL" wrote

>> You should definately learn the tables... A dive computer is handy -- but
>> if hte battery dies, and you haven't done your
>> tables.. well; what's OK for next dive?
>
> Hmm, I did a dive yesterday with a maximum depth of 30m and a bottom time
> of 38 mins. If my computer failed what's OK for the next dive on tables?

Assuming you did not blow off decompression during the dive, there's no
problem. Take out your tables and pick whatever the highest repetitive dive
group is. Use that to plan your surface interval and next dive.

While it is not usually possible to go from a multilevel dive computer to a
specific repetitive dive group on any table, it is normally possible to go
to a group that is at least as conservative as your actual condition. If
you have not incurred a deco obligation that you failed to meet, then the
highest group on your table has to be as, or more conservative than your
actual group and, accordingly, can safely be used to plan your next dive or
dives.

If you do not know whether you met all deco obligations on a previous dive,
then you really should have been paying more attention to what you were
doing, and what your computer was telling you, during that dive and,
frankly, are probably not competent to be planning a next dive until you've
met the surface interval requirements of whatever computer you chose to use
for the subsequent dive.

Lee

Dennis Willson wrote:
> -hh wrote:
> > gocart <harlanjs@pacbell.net> wrote:
> >>At this point I'm leaning away from it.
> >
> > I'd really recommend a cheap (under $300), simple (ie, not an "Air
> > Integrated") computer.
> >
> I really like my air integrated computers. I know people that think they
> wouldn't like it, but none of the people I know that say that have
> actually used one.

I seriously looked at them several years ago, and at that point in
time, pretty much all of the available products' interface designs were
dangerous, in that they failed to clearly differentiate between time
remaining due to air and time remaining due to no-deco limits...most of
them did a "lesser of", whereas some actually blinked back and forth.

>From a human engineering interface design standpoint, this is a Bad
Thing, particularly when you consider the likelihood that the operator
is likely to have some nitrogen impairment. Hopefully, they've gotten
less bad for their interface designs.

In any event, AI's generally cost more - - sometimes a lot more - -
than a non-AI, and when you look at it from a (Price:Performance)
standpoint, the potential of an extra 5-10% of bottom time at 150%-300%
the price doesn't offer a good "bang for the buck".


> The thing I really like about it is that it will show you how much time
> you have left and it will calculate based on current air consumption...

Because the current air consumption rate must be averaged across some
time period, it will either be overly sensitive, or suffer a response
lag. Both lead to questionable predicdtions and over the years (check
the archives), there's been many critical comments about the devices
providing misleading dive information. YMMV, but a device that
delivers bad information is IMO worse than not having the information
at all.


>This really helped me early on in my diving for learning breathing techniques.

Which would appear to suggest that you would probably agree that the
air consumption rate feature may very well then be of less value for
experienced divers?


> Also another option I really like is the computer link. It allows me to
> download my dives to the computer showing graphs of the dive profile.

At an additional cost of usually around $100 (Suunto), since they often
don't come standard with the dive computer itself.

YMMV, but I consider Les Wilk's dedicated datalogger, the "Sensus", to
be a much better value product, as not only does it include multiple-OS
support, but it has 5x the data logging capacity. More info on the
Sensus can be found at:

http://reefnet.ca/products/sensus/

BTW, I think Les probably has a typo on his webpage...I think the new
Sensus Ultra only will log 200 hours @ 10sec interval (not 2,000
hours), as this would be double of the 100 hours @ 10sec that the
Sensus Pro does.

Also, the Sensus also uses an *open* file format that's very easy to
export into other applications for doing whatever you want: within his
GUI, you can do a copy-n-paste into MS-Excel, for example.


-hh

nitespark <nitespark@cox.net> wrote:

> -hh wrote:
>
> >
> > I seriously looked at them several years ago, and at that point in
> > time, pretty much all of the available products' interface designs were
> > dangerous, in that they failed to clearly differentiate between time
> > remaining due to air and time remaining due to no-deco limits...most of
> > them did a "lesser of", whereas some actually blinked back and forth.
> >
> I have an Aladin AirZ Nitrox (hoseless AI). Mine shows remaining
> no-deco time, shows remaining gas, and shows how much time I have left
> at that depth and safely make it to the surface.


To clarify, you mean that this particular dive computer model shows
three numerical values simultaneously at all times?

IE: (minutes/no-deco), (PSI), and (minutes/air-consumption)?


-hh