Discussion in 'Buoyancy Compensators (BC's) and Weight Systems' started by richies, Sep 16, 2003.
Does anyone have any pictures of the Watergil Atpac BC they could post here please?
"Watergil" - now that's a voice out of the distant past!
I have one, but no photo of it.
Watergill was current in the early 70's and was light years ahead of its time. The Watergill Failsafe System had a regulator that would sense if the diver stoped breathing. Pressure would then build in the first stage, and slowly inflate the BC automatically, bringing the unconsious diver to the surface. I am not kidding. Then once on the surface, the regulator would emit a honking sound to attract attention. Here is a photo of a (huge) Watergill second stage. I think that I have a photo of an AtPac at home. I'll post it tonight.
I dove with an Atpac in the early 80's and still have a couple including one with the fairing. One is still fully functional, the other is pretty much spare parts.
It was ahead of it's time in terms of being back inflate and weight integrated. It was also quite streamlined with or without the fairing. And oddly enough, the LP disconnect fitting is essentially the same as the current industry standard.
The weight integration invloved fairly large diameter lead shot in a hollow backpack. It had a ripcord at the bottom that realeased the stainless steel bottom to the back pac allowing the shot to fall free. The extra space in the pack was filled with glass marbles which were near neutral in bouyancy and prevented the lead from shifting during the dive.
The problem with the sytem was a tendency for the shot to form a self supporting arch and fail to fall out of the pac when needed. Smaller diameter shot resolves the problem.
The inflator hose was low profile and low drag with most of the LP hose inside the hose itself. This was quite streamlined and needed only avery short LP hose. But the inflator hose also incorporated the over pressure relief valve which was a bit on the small size for a 45 lb wing so in the extreme case a wildly out of control ascent from deep water could potentially blow the bladder.
The early Atpacs used what amounted to an old style oral inflator mouthpiece with a power inflator attached ahead of it on the hose. Later Atpacs used a more modern inflator assembly but also moved to plastic fittings for the inflator and the OPV/inflator quick disconect body. These fittings had a habit of cracking and were the reason many Atpacs ended up out of service.
I saw an updated Atpac on sale on E-bay a couple years ago. It incorporated a more modern BC style set of shoudler straps and cumberbund and actually looked pretty modern.
A couple of comments. The tendency for the shot to form a self supporting arch was easily worked around by using small (about 1/4 inch OD) shot and not quite filling the back with shot and marbles so it could be easily shaken and kept loose. Besides, no decent (Ooops, that'll bring down a few comments!) diver ever had to dump his shot.
A far more serious defect was the LP hose internal to the airway. Both my daughter and I had the fitting on one end corrode and let loose during a dive with the result that the wing filled uncontrollably with air. Fortunately, in my case it occurred on the surface at the end of a dive. My daughter was also fortunate - while it occurred at about 50 feet, it was at the beginning of a dive when she had little decom risk; she just spread-eagled to slow her ascent as much as possible and breathed - probably faster than usual. <G>
I loved the AtPac and never converted mine to a vest. I abandoned it when I started travelling a lot to dive and got tired of carrying lead shot with me. My rig for many years now has been the AtPac wing with a standard airway and power inflator, a pair of soft cam-bands from another BC, and an old-fashioned tank back pack with 2 inch nylon straps.
Here is a photo of the front side of an AtPac with the shell attached. These were intoduced in 1972.
Here is a picture of their amazing Failsafe first stage. It is two balanced piston regulators in series to form one big regulator. Either piston can fail and the regulator will still work.
The DIR guys would love it.
Where can I get one??
Thanks a lot guys, fascinating stuff!
all the best
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