Free Flow...

[tstormdiver]

Sounds like you handled the situation very well. I had my first free flow a couple of years ago while in my Adv. Nitrox & Deco class. I was in doubles & my instructor had directed me to simulate a primary regulator failure. The water was 42 degrees & I had a tough time reaching my valves with all the insulation on. I had to use my left hand to pull my wings up towards my head to reach the valve with my right hand. When I shut it down & switched to my back up, I accidentally tapped the purge button of my secondary regulator. That's all it took. These are ScubaPro MK25/ S600 regulators they breathe & will purge VERY easily. I used my left hand to hold part of the mouth piece out to prevent injury from the rushing air. My instructor was there in a flash, but I was fine breathing the bubbles. We both swam to the surface from 95ft where we got thing back under control. We then went back down & completed that portion of the course. He was amazed I didn't freak out on him. Without doubles I would not have had enough air to go back down. A free flow can drain a single tank in a hurry. Could I have taken care of it below? Perhaps,.... I don't know, it was so violent with the bubbles, I wasn't sure what was going on for a few minutes. I have done over 200 deep dives in that quarry & all of them have been at that 42 degrees. That was my first & hopefully last one I'll have, but at least I know what I can do whether I swim for the surface or stay down to correct the problem.

 

[CamG]

Greetings CattMollins and welcome to the world of cold water diving! Free flows go with the territory and training for them is essential. You handled it well and have learned from the situation. Apply these lessons to make dives safer in the future.
Breathing control is very important in cold water and having environmentally sealed regulators is as well. You can make any regulator free flow if you over breath it. I have tested this and it is not as hard as you think.
I have been on several dives where free flows have happened. Most were accidentally bumping the purge! In cold water try not to use the purge unless absolutely necessary.
Try to focus on blast methods and not over breathing.
One thing that is really important is a redundant air system. I do not dive waters under 50º with out a pony bottle big enough to get me to the surface or safety stop. I will not dive below 60' feet with out redundancy either, just my self imposed dive rule.
If you were diving wet it is easy to over breath as a result of the cold. Just take your time to gain control and plan your dives to keep the physical stress to a manageable level.
I personally had my first free flow at 99' yesterday as a result of over-breathing a second stage that was not properly set for cold water. It was not a big deal water temps were 38º-40º so I was not shocked when it started to hiss and then flowed. I just leaned forward allowing bubbles to go around my head and shut down my left tank and switch regulators to my right tank very carefully, using the blast method. I then turned the dive and we ascended to 60' where I re-opended the left tank carefully and it was fine. I know that exertion was the culprit but also that the second stage is set far to light for cold water.
Research cold water diving, practice the skills and gain mastery, and do not be shocked when and if a issue arises. Just deal with it. The reason we train is to minimize the risk of the environment in which we dive. Congratulations on your training that you obviously obtained. You were paying attention and now you understand even more clearly why you stay close to your buddy! I would recommend purchasing a redundant air system though but that is just my opinion.
You handled the situation exactly as you were trained so, KUDOS!
CamG Keep diving....keep training....keep learning!

 

[elan]

Here when the water is always sub 40 it's not a question whether you get the free flow or not it's when you get it. We were diving yesterday in 37F and had 3 free flows at 80 ft. My buddy had a free flow on his stage (which happens quite often with his S600 at that temperature), I got 2 free flows on my Flathead VI es (stage and the left post) which was quite unusual. In my case turning the regulators off - having them warm up a bit and turning them back on helped- they were working w/o problems after that at the same depth. Free-flows are easy to get if you do not handle the regulators properly. If you get a drop of water inside the reg somehow, say some water in the valve due to condensation, or from the previous dive, or the water got under the cup that can be sufficient to get a free flow.

If you dive cold water learn how to handle free-flowing reg and have redundant sources, - that gives a lot of flexibility.

 

[Big Gonz]

It looks like the Sherwood is Siiliar the Atomics. I dive the M1's which is also a Sealed Piston and Have yet to experince any problems but I still am leary about them. I also have a Scubapro MK17-G250v which is a diaghram True sealed reg. The Piston reg's Atomics atleast are sealed by packing the inside with Tribolube which acts as an antifreeze protectant. And is not totally sealed. But I have dove the M1's in waters down to 38 so far with no issues but I also bring the MK17 on my other one just in case and If i make it to Ice diving I would only use the MK17.

I have to agree on the Mk17/G250V combo. I was diving a MK25/S600 combo and that thing lasted 12 minutes in 43 degree water before free flowing. My dive buddy used the MK17/G250V combo without issue at all. We swapped air and went to the surface.

 

[RTee]

Elan...how do you like your FH VIs. I recently bought a pair and mounted them on Faber HP 117 doubles. So far they are working fine mounted as such and also mounted on a single first stage that I used on my ice diving course. From what I gather from your post, it seems to be the exception to the rule for them to free flow.

 

[elan]

Yes I was actually surprised, I think I got moisture in the first stages (most likely condensation) as I did not dry them under the DIN caps an sometimes tiny bit of drops manages to get in there. The fact that after stopping the free-flow and giving them some rest everything was working nice. This is the first time I get the regs flow in such a temperature. I had it many times down to 100ft in 36-37 water in St. Lawrence and Georgian Bay with -10-15C on the surface and they performed flawlessly, but at those times I was really paying attention to them being dry inside out. I love them, They perform well, I compared them to my buddy's MK17/G2500V and my wife's Apeks Tek3/XTX50 and have not found any difference performance wise.

 

[AfterDark]

I've had a few free flows with my MK V through the years. Most of the time I can take it out of my mouth bang it on the heel of my hand stop the free flow and continue the dive. I always get it checked after the dive. Better free flow than no flow!

 

[a22shady]

I agree it can happen to anyone at anytime. But as you said your buddy's S600 free-flow more then your's.I have to believe it's due to the 1st stage not necessarilly the Second. Having the Proper Reg for the Diving makes a differnce also. I have yet to have any issues with MK17/G250V neither has my G/F who has an S600 as her Back-up. I think for cold water diving a Sealed Reg is very important. I also have a set a Atomic M1's only done 2 dives on them but have had them in water temps in Low 40's so far with no problem's.

 

[elan]

I agree it can happen to anyone at anytime. But as you said your buddy's S600 free-flow more then your's.I have to believe it's due to the 1st stage not necessarilly the Second.

No it is due to the second. S600 does not work well in waters colder than 40F

It is sitting on MK17 and MK17 works well in those temps. He has 2 more regs which are G250V/MK17 and had no issues. This one flows quite often.

 

[tstormdiver]

I have MK25/ S600's. I have probably 200- 250 deep, cold water quarry dives in them, & except for that one freak time during that class, I have never had anyother free flows with them. I just dial the resistance knob down a bit & go. I also watch to make sure I'm not "over loading" the first stage- aka inhaling & using the inflator at the same time. I am now more prepeared to handle another freeflow, if it should happen, but overall have found the MK25/S600 to be adequate.