- REBREATHERS - SPORT DIVERS ... - Stingray Divers

Dive Computers for the Recreational CCR Diver
The advancement in dive computer
design, type and capability has come a long
way from the first Orca Edge, an air only,
brick size computer that was considered
state of the art in the early 1980’s. Today,
dive computers not only come in units the
size of a wrist watch, but also have the ability
to work one, two, even three mixes during a
single dive in both air and nitrox percentages
as high as 99 percent.
For the recreational CCR diver who is
mainly interested in keeping to depths
within 130 feet, can pretty much get a way
with a run of the mill nitrox computer. The
downside is that, that diver must adhere
to the FO2 percentage programmed into
the computer that matches his/her PO2 at
the max targeted depth of that dive. For
example, that max depth of the dive is 80
feet, the diver is going to run their PO2 at
1.3, which will be equal to 38%, that diver
should conduct their profile for the dive as is
to conduct as having only 38% regardless if
of weather or not they go no deeper than 60-
70 feet. That is with a one gas computer.
Two and three gas models, most of which
run below the $600 range, allow the same
diver to design a profile with a bit more
flexibility. The first setting will be reserved for
the bottom PO2 mix equivalent, the second
mix setting can act as either their deco mix
or as richer mix setting for the second half of
the dive, if the diver plans to work his or her
way shallower as the dive progresses.
Two Mix Nitrox Computers:
Dive Rite NiTek Plus & Duo
TUSA IQ-700
Apeks Pulse & Quantum
Cressi-sub Archimedes II
Suunto Vyper2/wristwatch model D6
Uwatec Tec 2G
Three Mix Nitrox Computers:
Oceanic VT3/wristwatch model Atom 2
Aeris Elite T3/wristwatch model Epic
Suunto Vytec DS/wristwatch model D9
Note: When it comes to labels, the Dive Rite
Duo, TUSA IQ-700, Apeks Pulse and Cressi -
sub Archimedes II are all essentially the same
computer built by Seiko. Oceanic and Aeris
computers are manufactured by Pelagic Pressure
Systems, of San Leandro, Calif., whereas both
Suunto and Uwatec are manufactured uder their
own name.
Computers Specifically Designed for CCR’s
Currently in Production
Cochran EMC 16/20H www.divecochran.com
HS Explorer - www.hs-eng.com
Shearwater GF - www.rebreather.ca
VR3 - www.vr3.co.uk
New Computers on the way
Dive Rite NiTek X - http://www.diverite.com
Liquivision X1 - http://www.liquivision.ca
OMS DCAP-X - http://www.omsdive.com
CCR Specific
There
are a lot
of decent
opencircuit
computers
out there.
But, once
you go
beyond VR3 with Spectrum color LCD
mainstream
and into more specialized systems that get
into constant (or semi-constant) PO2, the
game changes completely.
All are aimed directly for CCR’s with
most providing the ability to run a gambit of
gas mixes from air to heliox for both open
and closed circuit diving applications. With
the exception of Cochran, these systems
have the further ability to monitor a CCR’s
PO2 progression (via a cable linkage to the
rebreather’s O2 sensors), as well as run
real time gas calculations. The downside
of course is cost with most these models
running between $1,400 and $2,000.
If your plans don’t see you moving out of
the recreational range and into the world of
trimix, but you still like something beyond a
basic one-gas or two-gas nitrox computer,
two options with programmable PO2 set point
features under a $1,000 include: Cochran
EMC 16, manufactured by Cochran Undersea
Technology, and the VR2 manufactured by
Delta P Technology.
www.underwaterjournal.com June/July 2007