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Mares 22 Abyss Problems (SEP Issued Regulator)

Jan 09
Mares 22 Abyss regulator.

Mares 22 Abyss regulator.

Memo issued by the NOAA Diving Control and Safety Board on January 9, 2018

NOAA Divers,

Last month (December 7th, 2017) NDC Manager David Kowalick sent out a message informing divers of three incidents where the demand lever in the body of the second stage had detached. The regulator is unable to deliver breathing gas if the demand lever comes detached.

The demand lever is located in the second stage body and opens the valve that allows breathing gas to flow into the regulator. The lever moves when the diaphragm is depressed or when the diver inhales through the regulator.

In all three incidents, the problem was discovered on the surface during pre-dive checks or before pre-dive. If the demand lever were to detach mid-dive, it could be catastrophic. The primary regulator second stage would not be able to deliver the breathing gas. To this end, the NDCSB has the following requirements and recommendations.


  1. During annual review or in the next month, all UDSs will review this issue with their divers and report to their LODO when divers have been apprised of the problem and solutions.
  2. Divers will incorporate checking functionality of the second stage of both their primary air source and RASS during the pre dive by:
    1. checking for rattling coming from the regulator second stage body; and
    2. depressing the purge button of the regulator (this should already be something you do during pre-dive).
    3. Any problems should be reported to the NDC and any problem regulators should immediately be returned to NDC for inspection and repair.
  3. The proper response to this type of second stage failure underwater would be that the diver switches to their SS1 or goes to their buddy to air share or deploys their RASS. These are all skills that are practiced during the annual skills review and should be highlighted due to this issue.


  • Divers could carry the RASS as an additional alternate air source.


The inside of a Mares 22 Abyss diving regulator

The lever inside the Mares 22 Abyss regulator.




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