TESTCENTRE
More than lip service
Rebreather Safety Mouthpiece
COMPANY : AP DIVING TEL : 01326 561040 PRICE : £ 55 WEB : APDIVING . COM
Earlier on in the year , a BSAC webinar delivered by diving consultant Paul Haynes focussed on the potential for a CCR Mouthpiece Retaining Strap ( MRS ) to save a diver ’ s life in the event that they lost consciousness . Although these have been available for many years , there has been only a relatively limited uptake among the recreational community , which is probably due to limited appreciation of the benefits combined with poor ergonomics of existing devices . Hopefully the webinar , recent articles in this magazine and inclusion in BSAC ’ s new CCR course should help with the first of these issues .
Evidently , AP Diving is also aware of the discussion and has released an improved variant of its MRS , which it calls the Rebreather Safety Mouthpiece . I ’ ve been fortunate to have had one of the very first production models , so I had the opportunity to trial it on a number of technical dives , including the pilot of the new BSAC MOD 2 course . About 10 dives in , including some with lengthy decompression , and I can declare myself a fan !
The first major change over the previous version is that it replaces the entire mouthpiece rather than simply holding the existing one to your mouth . This allows it to provide a lip guard , which results in a much-improved seal around the mouth . I tested this by easing the pressure exerted through my lips . Initially I was quite wary , but soon grew in confidence when I realised how effective it was . Obviously , it may have been different had I been been unconscious , or possessed different facial features , or facial hair . There is , after all , no such thing as a standard face .
The other change is the neoprene ‘ slap strap ’ that rests easily below the crown of the neck and is tightened using the two straps either side of the head . These are a decent width , so work well with gloves and I found them effective in getting the correct level of tension . This is helped by the two swivels near the mouthpiece , which allow it to self-adjust to the optimum angle . The wide strap also distributes the load , doesn ’ t restrict head movement more than normal and was so effective that I soon forgot I was wearing the Rebreather Safety Mouthpiece .
Most of my diving takes place from RIBs , so I had a slight concern about the in-water de-kitting process , but there is a quickrelease clip located on the right-hand side to support efficient removal . After my first attempt I found this very straightforward , but it is also possible to release the adjustment buckles , which would allow the strap to come up over the head .
CCR divers also need to use bailout , and this will depend on which mouthpiece is used . For those using open circuit bailout ( OCB ) it will make no difference , but there are two options for the standard mouthpiece . The easiest way is to simply use the quick-release clip , but that does require one small additional step . As a test , I found that I could stretch the neoprene strap sufficiently to remove the mouthpiece so that it ended up below my chin . Although this allowed me to breathe from an open circuit second stage , it wasn ’ t particularly comfortable . So , I would advise against using that technique . Dom Robinson
SCUBA SAYS
This is a well-designed and comfortable piece of equipment that should improve the mouthpiece seal for most CCR divers . It now ships with all new AP rebreathers , but I ’ d encourage existing owners to consider the benefits that it can offer them , should they suffer loss of consciousness while in the water .
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