Free flow at 75 feet

[StuartT]

Yesterday myself and 4 other divers were at Pavillion Lake in B.C. to see the fresh water coral(microbilites) formations that are there. Actually there were more than 4 others but for the sake of this incident there were 5 including myself for the dive. One buddy team of 2 and a 3 team. The dive plan was to go south to 100 feet then west parallel to the shore to look for the microbilites that live on the slope in this particular location of the lake according to one of the group that dived here before. The turn point was to be determined by the newest diver in the group diving an al 80.

I had arrived the night before and already done a shorter(43 min) night dive at a different location of the lake and saw some of the rare coral formations. I still had 1900 psi in my steel 130 from that dive along with my half full 40 cu ft pony and was planning to do the first dive the next day with that gas supply. Partially beacause most of the others were on 72's or 80's and some were fairly new divers and I thought I would have plenty of gas and I only had 1 other full 130 with me for the second dive. At the last minute I decided to switch tanks and dive the full 130 instead as there was a chance no else would be doing a second dive that day. The other choice was to leave my pony on shore as I felt I had plenty of gas for the planned dive with a good reserve. What I didn't plan for was at about 15 min into the dive I took my reg out for a photo op and it started free flowing and I couldn't stop it.

I tried turning it down towards the bottom, putting the lever back to the pre dive position but it wouldn't stop. One of the divers from the 3 team was closest to me and was the one taking the photos so she noticed that i was freeflowing and pulled out her octopus and offered to donate it to me. I signalled that I was ok and continued to breath from my freeflowing primary taking it out between breaths trying to stop the free flow. I forgot to try tuning down the primary with the dial on the side but more more interested in getting to the surface safely with my rapidly depleting gas supply. Also didn't think to try closing then reopening the valve which was suggested afterwards. I signalled to abort and continued to breath the freeflowing primary slowly ascending and paying very close attention to my gas and how fast it was going down.

The buddy closest to me continued the ascent with me offering to donate her octo several more times but I was ok breathing from the freeflowing primary for a minute or 2 then I switched to my own octo. I guess in the back of my mind I thought it better to either breath from my own freeflowing primary or my own perfectly functioning octo than to air share with another diver as I felt like I was handling the emergency fine and her octo was there if I did completely run out. When we got to around 20 ft my primary stopped freeflowing so I switched back to it and signalled that we should do a 5 min stop incase we had come up a bit fast. My tank had gone from about 2800 psi to 600 psi in about 3 minutes.

I quite regularly switch regs during dives either to my octo or my pony reg just for practice and I think this helped me in this situation by not panicking and also the fact that my buddy for the ascent didn't panic and stayed with me for the remainder of the dive. Upon inspection after the dive my first stage was at 160 psi which is high but was within the year since last service. Fortunately our dive tech was on site and tuned my primary down so I could do another dive. He was unable to tune down my 1st stage on site but I trusted that I could do another dive on my regs being tuned down plus I would be taking my pony and my 1900 psi 130 on the next dive. I'm glad I did the next dive to kind of work out the bit of anxiety from the freeflow incident. What I learned from this incident is that we should all practice regulator swaps more often as well as mask drills and other skills taught in certification.

 

[jar546]

Very scary how much air was used up so quickly during the free flow. Is it a cold water reg?

 

[USVet96]

StuartT : glad everything worked out and you are ok.

That's a really, really good story about a situation occurring that could very easily spin out of control, but DID NOT because you handled it with proper training and keeping a cool head (not panicking).

I commend both YOU and your BUDDY for staying calm, and staying together until everything was resolved.

Great point as well at hammering home the importance of training and preparing for contingencies should they occur.

And I agree 100%, and i think others will as well, especially with the higher than normal rate of incidents lately, that more training and more time need to be spent on drills and situational awareness, and on what to do if an emergency happens.

Safe Diving

 

[TSandM]

Curt Bowen did an experiment to see how fast various failures would drain a tank, and the article on that is HERE. The bottom line is that you don't have much time, and the deeper you are, the less time you have.

Freeflows can be caused by grit or sand in the second stage, but probably more common in cold water is a first stage freeze-up. It is not an unreasonable thought to carry a redundant gas source when diving very cold water in single tank rigs. Air-sharing, although obviously necessary if the person with the freeflow runs completely OUT of gas, may induce a FF on the donor's first stage as well. If I recall correctly, there was a double fatality in the midwest a few years ago due to this.

You did a number of things very correctly here: You made a prompt decision to abort the dive, continued to breathe off the freeflowing regulator while also attempt to get the flow to stop; you went to your non-freeflowing octo, to make your life easier, and you stayed with your buddy, so that if you actually ran OUT of gas, you would have a gas source.

The only thing I have to add is that you can sometimes get freeze flows to stop if you stop the flow of gas through the first stage. So taking your buddy's octo and shutting down your tank would be an option, and waiting a minute or two to see if the reg would thaw. It's not a good option if you are severely stressed, or if you are uncertain you can execute an air-sharing ascent under control -- or if you have a real concern that conditions are cold enough that the double demands on your buddy's reg might cause the same problem.

 

[kenns]

Yes, the regs were cold water but the bottom temperature was only 45F. As Stuart's buddy, this was a very good experience and am so glad that nothing serious happened. I had LOTS of air for the both of us to make a safe ascent. I'm a better diver for this event and as Stuart said, the second dive was really important for us. It was the most relaxed dive of the whole weekend.

 

[markmantei]

Stuart,

You did a commendable job of dealing with this potential emergency. Staying calm, analyzing the situation and taking a good, reasonable course of action. I don't remember who I am quoting from this board, but, "Stop, breathe, think, you have the rest of your life to resolve the problem"

There are several threads on this board of incidents where the diver did not take the appropriate steps that you did, so kuudos to you. Its a good thing that you had decided to take the full HP130, better to have too much gas than too little. Also lucky that the issue happened early enough on in the dive you could safely ascend without needing your buddies octo, although with how well you handled the incident up to that point I'm sure that would not have been an issue either.

I forgot to try tuning down the primary with the dial on the side but more more interested in getting to the surface safely with my rapidly depleting gas supply.

If you are refering to the cracking pressure adjustment, you are right that it is possible that could have resolved the issue underwater. My buddy had that exact issue 2 weeks ago, but I was able to detune it and resolve the issue underwater, although we still ended up ascending with him on my octo as he was down to 200psi by the time I fixed it (he was on an AL80, I had an HP130). Quite amazing how fast a free-flowing reg will empty a tank.

 

[StuartT]

Very scary how much air was used up so quickly during the free flow. Is it a cold water reg?

Yes it is a Zeagle cold water reg and as Kerry said the temp at depth was only 43-45 fdepending on who's computer. Our tech thought the high psi of the first stage along with the pressure at depth caused the freeflow.

 

[StuartT]

Thanks Lynne for editing my post into paragraphs. Here is a bit more detail from the data downloaded from my computer. Max depth was 93ft but it's a lake at 2400 ft elevation. I was diving 32% nitrox and my computer adjusts ndl's for altitude (22 min @100 vs 29 min at sea level). For some reason the dive profile graph shows end dive gas at 1930 not the 620 as on the summary (wierd). The fastest ascent of the dive was from the 15th to 17th minute going from 64 ft to 19 ft. the next 6 minutes was spent between 20-12 ft. I don't think I had a freeze freeflow but don't know for sure but I dive that reg all throughout the year in the PNW. 2 things that have been mentioned would be good info for others to try if it ever happens to you. 1 is to try sticking your tounge or thumb to try and stop it and the other is if you are comfortable doing it breath your buddies octo while you turn off the tank and turn it back on.

My main thoughs were that I need to get safely to the surface and didn't think of those at the time. I would also like to add that it is from reading posts here on scubaboard that I knew I could breath from a freeflowing reg not from any formal training. Prior to reading that here I thought you could only sip air from the side of the mouthpiece that's taught in OW so hopefully someone else will benifit from this in the future. And thanks again to Kerry for being a great dive buddy (who wasn't my official buddy for the dive)

 

[OldNSalty]

Sip air from the side? I have never heard of that. Is that the standard from some agency?

Glad you did OK.

 

[stairman]

Glad things worked out ok. These problems are always learning experiences. I probably would have shut down the reg and airshared to the safetystop and then maybe turn it back on to see what happens. After sticking my finger in the mouthpiece to try to stop it, trying to detune it etc. Stress seems less when the freeflow is addressed for everyone and practiceing shutdowns and airshare ascents is also a good idea.