Here is a cautionary tale: Always, always, always at very least rinse and dry your rebreather hoses before storing them
A few weeks ago, I was suffering from the tail-end of an upper respiratory tract infection – one of those late-in-the-season cold viruses that leaves your throat raw and your sinuses bloody. Anyhow, it really was nothing too serious but at some point during the development of that infection – and I cannot remember exactly when – I had to do a little sortie and used a rebreather. For some unknown reason, I did not do the usual post dive rinse and dry, but left the unit assembled thinking I would take it back into the water a couple of days later. I did not. A few days later I was too sick to dive.
A few days further on, I was to fly off to do some open-circuit training in the Keys and hurriedly disassembled the CCR, rinsed it, and packed up its bits and pieces into storage. It is important to note that I did not wait for it to dry before packing it away.
Now if you are a nurse, medical doctor, epidemiologist, pharmacist, experienced CCR diver or sensible human being with a modicum of common sense, you probably know exactly where this little tale is going.
Last Friday, I unpacked and assembled, loaded and ran the usual tests on my CCR prior to taking it diving on Saturday. I had volunteered to help place the mooring buoys on local wrecks and opted to use CCR because of a number of factors not least of which was warmth.
Everything went fine. No real issues as long as we don’t count a crappy HP seat on the first stage regulator on the oxygen side on the unit. (Something easily fixed with the hurried purchase of a ScubaPro Mk11 balanced diaphragm first stage.)
Made the five-hour drive home Saturday night and pottered around the house Sunday, sorting out dive gear, working in the garden, doing some grocery shopping, playing guitar.
Woke up Monday with a déjà-vu tickle in my throat; and by Tuesday evening had a fever and spent most of the night lost in dreams that could have been art-directed by the love child of Stanley Kubrick and Lina Wertmüller.
Now here’s the thing; I lean more towards OCD than laid-back when it comes to disinfecting dive kit. TriGene and Virkon S are my friends. I carry a little container of dilute Detol and full-strength Listerine in my save a dive kit. I have a special towel (Shamwow! in case you are taking notes) for drying the inside of the scrubber unit, and have a portable hair dryer although I have no hair.
But I screwed up. Now, you may have all sorts of arguments to the contrary, and you may have solid evidence that the average URT virus or bacterium cannot survive in a warm, dark environment for a week and a half, but I believe that by putting the counter-lungs, mouthpiece BOV and hoses away damp and NOT fully disinfecting nor drying them, I condemned myself to a few days of unpleasantness. It will not happen again.
For the record, there seems to be nothing approaching a standard in the dive community for cleaning and disinfecting “the Loop” after use; but here is the technique I NOW use… and from here on in this is the EVERY-time protocol.
Concentrate efforts on counter-lungs, corrugated hoses, connections and BOV including mouthpiece, but also be careful to clean the scrubber and head. Rinse whole issue with fresh, warm water. Remove excess water, spray with disinfectant (Virkon or RelyOn the fit-for-humans equivalent was the only one endorsed in a 2002 study conducted by the Canadian Military). Leave for 10 to 15 minutes, rinse and air dry then finish off with warm air from a small hand-held hair dryer. Store.
Now here is an additional protocol. If the unit has sat unused for more than a couple of weeks, spray once again immediately before use with disinfectant, let sit, rinse and shake out excess water, go use. Repeat as necessary.
Virkon S, RelyOn, TriGene (used by the Royal Navy) and Buddy Cleanse have all been highly recommended to me; I know that Virkon works (when you bother to use it). I have also used mouthwash to effect a quick and dirty clean up between dives, especially in fresh water which has the potential to harbor trace amounts of nasty little pathogens. However, alcohol-based mouthwash such as Listerine, does interact negatively with seals and other components so one has to be circumspect in its use.
I hope this little note helps you to avoid getting bugs in your breathing loop… because I have to tell you, this is one experience best enjoyed second-hand.