AP Diving Open Circuit Bailout Mouthpiece

An addition to the AP Diving rebreather range the Open Circuit (OC) Bailout Mouthpiece is a useful addition to your rebreather but at around £550 is it worth the cost?


Well for starters you can sell your old mouthpiece on Ebay or a similar site to off-set the costs, this should raise about £150 so the question should be at about £400 is it worth it?

The primary advantage of this arrangement is that in the event of a bailout you can simply swith the unit from closed-circuit to open-circuit operation and not have to worry about closing the mouthpiece, finding the bail-out located on the corrugated hose, etc, etc., so it does reduce a level of stress which has to be a good thing.

However for those of you who will switch gases when you bail out, for example switching to your on-board oxygen at a suitable depth, to minimise deco obligation, there is no quick release attachment on the mouthpiece, it is permanently 'plumbed into' your diluent, meaning that you will need to use the other bail-out mouthpiece when you switch gases.

Diving with this equipment there are two things that are immediately apparent:-

i) It is larger than the 'old style' mouthpiece so obscures more of your 'downward vision'; and
ii) It is much heavier meaning that after a long dive you will have noticeably more tired jaw muscles:

On the first point you just have to balance the pros and cons, for you does the loss of part of your field of vision balance against the benefits of a built in bail out facility? For me the balance came in favour of the bail-out.

On the second point AP have acted and if you purchase today the set up has a strap which holds the mouthpiece close to your face, removing most of the additional biting and holding requirement, however I have an old unit so have to keep doing my best impression of a british bulldog.

The design of the mouthpiece is such that you must keep the twisting arrangement clean and free of dust a salt crystals, so for all of you 'dirty divers' you really must wash your unit thoroughly after each dive! I dump mine in a barrel full of fresh water overnight to make sure that there is no chance of any crystallisation.

You should also make sure that the purge is correctly set-up, there is nothing quite as annoying as a small stream of bubbles bleeding from the purge. It is a relatively simple task if you have the necessary tools and I would suggest that you set it up so that the WOB is relatively high, in that way there is no chance of any drifting of the set-up which will cause.....yes you have guessed, a small stream of bubbles etc!

As delieverd the corrugated hoses are fitted with weights and are at the maximum length, check the length of the hoses on your old set-up and cut the new hoses to length, long hoses mean an untidy set-up, additional restriction in the breathing loop and forces pushing the mouthpiece away from your face making worse the problem I highlighted above.

The existing HUD clip fits on the side of the autobail-out in a similar position to the old mouthpiece, however as the new set-up is much larger the display is further away and in your periperal right hand vision. To get a good line of sight to the LEDs I have had to take about 3mm from the bottom of this clip otherwise the LEDs are partially obscured.

If you buy this upgrade for your unit it is, in my opinion, a worthwhile purchase however please don't assume that it is a simple plug and play, you will need to spend some time setting the unit up, trimming hoses and clips to ensure that you have a comfortable and optimised set-up.

Richies rating 7.5/10 : A couple of issues but in general a well thought out piece of equipment that will be of benefit to AP rebreather divers. 

Recommended suppliers

Latest Photographs