Home Dive Training Alex Peirce’s Tech Tips: Why Does My Regulator Breath Wet?

Alex Peirce’s Tech Tips: Why Does My Regulator Breath Wet?

Tech Tips - Why does my Regulator breath wet - June 2018


Do your feel water enter your mouth when breathing in underwater?   Alec explains what the problem is and how to do an emergency fix before taking it to a service professional.

Sometimes a little bit of water is good when your throat is dry from talking but when breathing underwater and you get water coming in through your regulator into your mouth – is not good. 

There are two reasons why this is not good; first, it may a sign that there is something wrong with your regulator, which is not good for your head or health, and secondly, it tickles your throat. The saltwater definitely is uncomfortable since it sprays into your mouth causing you to start coughing. 

As a side note, coughing and sneezing underwater is pretty interesting. It is actually very hard to sneeze underwater since nothing really tickles your nose. 

Regulators breathing wet is not an uncommon problem – but what makes the regulator breathe wet? There are only two reasons why a regulator would breathe wet assuming it is not a major breakdown like the housing or hose are not broken. Assuming that the housing wasn’t cracked and letting the water in – there are only two ways. One way is through the diaphragm. There is a large rubber or silicone that is part of the regulator, soft rubber, that is part of the regulator, that flexes in and out as you breathe.  On the inside a metal part pushes against the lever that opens the valve that gives you air. This little circular piece of rubber is a critical piece of equipment. This is made of thin rubber and sometimes it gets tears and little holes in it although not common with the new silicon ones. The other part of the regulator is this little thing called an exhaust valve or mushroom valve, aptly named as it looks like a mushroom. Leaks are caused by one of these two things.

 How do you identify which one is the cause? If you are swimming upright and water is leaking in – it is the diaphragm. If you are face down with fins up high and water leaks in – it is the mushroom, exhaust, valve. So how do I know this? When you are breathing upright, the exhaust valve which is in the lower part has more pressure on it, it will seal and won’t leak. If it still leaks, it must be coming through the diaphragm.  If the regulator is upside down and you are getting water, the diaphragm now has pressure on it yet the exhaust valve has very little pressure, the leak is likely from the exhaust valve.

Of course, this isn’t one hundred percent the answer but it does give you an idea what you should do about it. Obviously, you would want to take it to your local dive store, right?! What if you are on a two week liveaboard dive trip with no technicians, parts, or service available? Liveaboards should have some of these services available – but regardless – you can take a look at it yourself. 

Here is what you do to start – most regulators are fairly easy to get the front cover off. Some regulators have secrets notches and buttons to press on which isn’t a bad idea. This particular regular we will demonstrate has a tiny little hole with a tiny little pin that goes into the hole to hold it in place. Pull the pin out and the cover spins off. Other regulators have little hidden notches while others require the cover to be peeled off. Suffice to say, there are various ways the front cover comes off – but that is the first step so you have to get that cover off. Keep track of all the small parts – there are plenty of them, like a friction ring, a diaphragm retainer ring, then you reach the diaphragm. In this example it is a clear silicon diaphragm. To inspect it you hold it up to the light and stretch on it as you go around it. You are looking for a hole. If you find a hole you have found the problem. What do you do now that you found the hole?  Tape doesn’t cut it but there are other quick fixes available. Silicon sealant can help, not permanently, but a temporary solution. Try it – put a little silicon sealant on both sides of the diaphragm on the hole and spread the hole a bit so the sealant goes through the hole. Once it dries overnight and with a bit of luck it might work.  Another less conventional method I have heard people use is saran wrap. Essentially you put everything back together and place the saran wrap over the diaphragm before placing the retainer over the diaphragm, then the friction ring, then lastly the cover. 

Suppose it isn’t a hole in the diaphragm so you may want to check the exhaust. Most regulators must have a way to get the exhaust exposed, sometimes from the inside and sometimes the outside. They are all a little different so you will have to explore it a bit. This particular regulator we are demonstrating has a pin you pull out. Once you pull that out a plastic piece comes off and then you find the rubber exhaust mushroom. Take it out and inspect for tears or holes. These are hard to repair and almost certainly you will have to simply get a new one. You can replace with a similar style -it does not have to be the exact brand you removed. They are all the same except for the diameter. If you do find one while traveling on the liveaboard – snap it in and now you have repaired your second stage!

Now we have covered a few ways why your regulator can leak water, how you know what is leaking and suggested fixes.