What are the advantages of OMS retractable band BC's and what documentation can you provide to support your claims?
OMS Retractable band BC's are easy to orally inflate *1
OMS Retractable band BC's assist in deflation *2
OMS Retractable Band BC's decrease drag when deflated *3
OMS Retractable Band BC's reduce the massive airshift associated with large non-banded BC's that occur when changing body plane. *4
OMS Retractable Band BC's have trim adjustability. That is by removing selected bands, differentially inflated parts of the BC can compensate for uneven weight.
The highly engineered OMS retractable and non-retractable band BC's have a proven safety record over a 10-year period and have been used under the most extreme conditions.
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Argo Diving Service (an independent test lab)
Po Box 2289
Avalon Ca 90704
By Jon Hardy
Date of Test: November 9, 2000
REPORT ON SEVERAL FUNCTIONAL aspects OF OMS BUOYANCY COMPENSATORS
BY John Hardy October 27, 2000
We received two Single Bladder BC's with two IQ (stainless) Back plates (IQ M-L), two aluminum backplates, and two single tank adapters with cam bands on October 23, 2000. We assembled each of them and confirmed that they were correctly assembled with a phone call to OMS. The only difference between the two BC is that one was assembled with the retractable bands and the other assembled without.
On October 26, 2000 and October 27, 2000 a series of tests were conducted to determine any functional differences between the two BC's. Jason Manix was the technician who assembled the BC's and wore them during all measured tests. Jon Hardy supervised all testing and assembly.
Tests were conducted in Avalon Harbor on Santa Catalina Island, California. All tests, other than the drag tests, were done in 24 feet of water. The test diver and/or the BC's were attached to a mooring weight to allow for control.
Oral Inflation*1
Both BCs were inflated orally without undue difficulty.
The BC with bands took an average of 16.5 seconds to dump the air put in orally.
The BC without band took an average of 15.0 seconds to dump the air put in orally.
(Conclusion) This test indicated no significant difference between the two BCs, yet it did confirm that either BC could be inflated orally.
Power Inflation
This test indicated no significant difference between the BCs, yet it did provide a basis for comparison with buoyant lift and rates of air dumping
Remote Exhaust Deflation*2
Each BC was dumped multiple times using the remote exhaust on the top right of the BC, after being fully inflated.
BC with bands took an average of 20.5 seconds to dump all air.
BC without bands took an average of 25.5 seconds to dump all air.
(Conclusions) This test indicated that the BC with the bands is more effective at dumping air by use of this R/E (remote exhaust).
Drag Tests*3
This test was devised to measure the approximate drag or resistance to movement through the water by a fully equipped diver with these two BC's (with and without retraction bands). The diver was secured by 15 feet of line behind a 25-foot commercial dive boat that was secured to a dock. The boat's engine was put in forward at an idle speed of 800 rpm, thus creating a current of 0.95 to 1.10 mph as measured by a calibrated underwater speedometer. Placed directly in front of the diver and attaching the diver to the line to the boat, was a spring scale. The diver took readings while in the current of the propeller wash at three to six feet underwater. The tests were repeated multiple times on two different days.
(Conclusions)
BC with bands caused an average of 6.3 to 11.3 pounds of drag when empty.
BC without bands caused an average of 7.5 to 11.5 pounds of drag when empty.
These tests indicate no significant difference in drag (when inflated).
Airshift*4
(Conclusions) The BC wings (without the bands) move more (the airshift in the BC) and are less stable (than the BC with bands). i.e. The BC wings with the retractable bands are more stable)
Summary
These BCs are well suited to tech diving with or without the retractable bands. Their buoyant lift capacity is significant and within specifications. Both BC's (with and without retractable bands) can be inflated orally and there is not significant difference in this aspect of use.
There is no significant difference in either the power inflating or the oral deflating of these BC's. The BCs do dump faster than they inflate, which are a positive safety feature. The remote exhaust on the top right of the BC flows better when the BC has bands, although the BC without bands was still acceptable.
