Larry Molnar (Cleveland, OH) thought we were
too dramatic when we wrote about the Zeagle recall
in October, suggesting that if a BCD buoyancy
cell split at the surface, the user might plunge to
the depths. He suggests a properly weighted diver
would stay comfortably at the surface.
This might be true at the end of a dive, but a
properly weighted diver would carry enough weight
to account for the loss of weight of the air used during
the dive. This could be as much as eight pounds
(3.5kg), depending on the tank. So if the BCD split
at the surface at the beginning of a dive when the
tank was full, down the diver would go.
In my days as a test diver, this happened to me
twice with prototype BCDs, where the buoyancy cell had not been welded properly. I can assure you, it
resulted in some hard finning upward!
Michael Lay wrote that two members of the
group he went with to Bonaire needed to take their
regulators to a dive shop for attention after the
checkout dive, even though they had been serviced
at home before the trip. The technician said he saw
lots of similar incidents, and told them it was better
to leave a three-year gap between servicing.
Michael says, "Given the high cost of servicing
gear, this would make sense. For the cost of three
service visits, I can usually replace the item for the
same amount of money. I would love to hear from
other readers on this."
It's common for a regulator appearing to need
adjustment immediately after a service and the first
dive. Any liveaboard dive guide will tell you how
often they hear a gushing regulator on the aft deck,
accompanied by the words, "I don't understand it.
I've just had it serviced."
While there are regulators that only require servicing
every three years (Atomic regulators come to
mind), most need servicing more frequently. The
problem arises in that the replacement valve (lowpressure)
seat used within the mechanism usually
needs to 'bed' against the metal or plastic orifice so
that the regulator will almost certainly need readjusting
after the first dive despite the best efforts
of the servicing technician to set it up properly.
There's a certain amount of engraving that takes
place, too, and that takes place over time.
A good technician might take several hours to
adjust a recently serviced regulator, returning to
it time and time again. Since time is money, this is
unlikely to happen. Regulators get serviced instead
to 'manufacturer's standards.' So what do we learn
from this?
It's best not to take a freshly serviced regulator
on a dive trip without using it first, even if it means
going to an inland site or even a sufficiently deep
swimming pool. Use it and take it back for adjustment.
While praising Atomic regulators for their long
service intervals, the same praise may not be due for the company's computers. Undercurrent subscriber
Kent Roorda (Grand Lake, CO) wrote:
"I just read the article about bad depth sensors
on Atomic Cobalt computers. Unfortunately,
the article comes as no surprise to me and many
other Cobalt owners. Atomic/Huish has replaced
my Cobalt five times; three of which were due to
bad pressure sensors. My wife's Cobalt has been
replaced three times due to bad sensors. They have
also had numerous other problems. My relationship
with the computer is a love/hate relationship.
I love it when it works, and hate it every time it
fails. Never -- until I purchased an Atomic Cobalt
computer -- did I feel the need to carry a backup
computer. But, in my opinion, a backup computer
should be included with each new Cobalt.
"We just got back from a liveaboard trip in
Komodo, and on that trip, the two other people
who had Cobalt computers experienced failures
with their depth sensors. Honestly, it is amazing
that, with such a high rate of failure, no recall has
been made."
Apparently Atomic Aquatics is aware of the problem,
but officially they are tight-lipped. Not a good
practice, when divers' lives are at stake, so until this
is resolved, divers in the market for a computer
might be wise to avoid the Cobalt. And if you have
one -- well, for sure carry a backup, a good idea
anyhow.
- John Bantin