The caustic
cocktail, a personal experience.
Many of us have heard the term used in rebreather
diving called the “caustic cocktail”.
From stories of just a bad taste in the mouth all the way to a lung full
of nastiness. Until yesterday I had just experienced the bad taste in the mouth
variety and then only once. Yesterday I
was doing a dive with my friend Kent, we hadn’t made any formal buddy arrangements
(I think divers in the PNW invented the term “same ocean buddies”) but just
happened to run into each other a couple minutes into the dive. We were poking
around the bottom of a wall at about 145 fsw, looking at very large urchin
shells that were no longer occupied. I
had about a minute of NDL left and began to move up the wall,
Kent was about
20 feet away and 10 feet deeper than me. Its
Interesting how fast things can change.
With absolutely no warning, one breath of gas changed into a breath of
liquid. I instantly had a mouth and
throat full of sodalime dissolved in sea water.
My trachea spasmed (that probably kept me from
drowning) and blocked the mixture from my lungs but sent some into my
stomach. Pulling the mouth piece out and
closing the DSV took a couple seconds and I was holding my breath and spitting
up into the water while the panic was rising in my brain. Fighting that off I knew I needed to breathe
soon and took hold of my Air 2 that was plumbed to my air diluent cylinder and
put that into my mouth, cleared it of water and took a tentative breath. Air is good.
I looked over at Kent and waved
my light at him a few times, no response, he was looking the other way. With only a 13 cf diluent cylinder, that was
not full when I started this dive (mistake one) I knew that I only had a few breaths
at the 135 foot depth I was at. I had
neglected to bring along a larger bailout cylinder (mistake two) as I was not
expecting to do any deco diving this trip.
I headed for the surface, keeping my airway open and exhaling any time I
was not inhaling off my very limited gas supply. At that point I wasn’t sure if I had the gas
to make it to the surface, but I decided that I was going to make it, no ifs,
ands or buts about it. I ascended the
135 feet in about 90 seconds, not the safest ascent rate in the world but the
options were, as you might guess, limited.
I hit the surface and waved to the skiff, not the usual diver OK but the
two hands crossing above the head distress wave. Al wasted no time getting
the skiff over to me and I climbed aboard all the while coughing, spitting and
vomiting my lunch out, and gasping for breath. I washed my mouth out repeatedly with fresh
water and asked for the onboard oxygen bottle, which Al handed down
quickly. I cranked it up to 15lpm and
started sucking it down. I was not
feeling any symptoms of DCI but wanted to nip it in the bud if I could. The length of my bottom time, 17min, the fact
I didn’t enter deco, 18 hours since my last dive and the relatively controlled
ascent was evidence that I probably wasn’t going to get bent, hard. I wasn’t taking any chances, I used the whole
cylinder. Then swapped my dil reg over to my O2 cylinder and started using that. By
that time most of the divers were up, but some had not heard the recall and
were still diving. I had this horrible
burning sensation in my throat and mouth, swallowing was near to impossible and
coughing hurt like hell. This was not
fun. Still no DCI symptoms, Colby, the
divemaster was coming by to check on my frequently and when Donny, the other
divemaster, returned to the boat from his dive, he took over my looking
after. He holds up three fingers and says,
“how many?” I
crossed my eyes and held up one finger back at him. His reply, “you’re back”. Donny knows my sense of humor.
A boat ride back to the Nautilus, off with the dry
suit, plenty of water, some medical attention from Kim, a nurse who was a guest
on the boat and a very sweet lady, (thanks Kim) and things gradually headed
back to normal. My throat was still
sore, everything, including water, tasted like crap, but with no signs of DCI,
I figured the worst was over.
Its now the next day and my throat is still sore, my
voice is mostly gone, similar to a case of laryngitis, and I am sitting out the
morning dive and writing this article.
I took the unit apart last night and found that my
scrubber lid was leaking. Either from
not being tight enough, or something caught under the seal. The unit had passed the positive and negative
pressure checks, but I'm thinking
that when it hit the cold water it may have shrunk the rubber seal enough to
allow water to trickle in, slowly filling up the canister until it overflowed
into the inhale loop. I felt no increase
in work of breathing, heard no gurgling, and tasted no difference in the loop,
until I had a mouthful.
My lessons learned:
Either fill the dil bottle before every dive,
or carry a bailout cylinder with enough gas to ascend at a slower rate. (This is of course only for recreational, no
deco, diving, I still carry 2 sling bottles on deco, deep, trimix dives).
In the end, the only thing that saved me was my
training and just plain stubborn determination to not die. I thank my original drager instructor, Alan
Studley, for the training that put me on this course of discovery into
rebreathers and provided me the tools to stay alive when the shit hit the fan. Thanks Alan.
My advice to my fellow RB divers,
previous performance is no guarantee of continued results. I told someone the day before this happened
that I had never had a flood of my loop.
I should have added the word, yet.
My mistake was not in having a loop flood, but in not being prepared for
that eventuality, yes I had some onboard dil accessible
from OC, but not near enough. If I had been delayed in my ascent for any
reason, I probably would not be here today to tell this story. The absolute number two thing in RB diving is
HAVE A BAILOUT PLAN. Number one is of
course know your PPO2.
Don’t just assume you will never have a flood. I HAD BECOME COMPLACENT!!!!! Don’t let this happen to you. I was lucky, and I had a survival mindset, its what brought me back.
Don’t depend on luck, have a plan that you know will work. How will you know it will work? Test it, see how long it takes you to
bailout, you can do this shallow and have a buddy time you, then do the math
for the same thing at depth, calc your OC bailout gas and then double that
number, carry it every dive, even when you are feeling lazy.
It is said that what does not kill you makes you
stronger.
Thanks to Mike Lever and the
crew of the Nautilus Explorer for their timely help, care and professionalism.
Ron Micjan
4 June 2004
Port Hardy, Canada