Tobermory Dive Operations

[elan]

By the way, what did you do in those situations? We were taught how to breathe out of a freeflowing reg, but were never taught it in the context of if it happens in the middle of a dive where you're not near the surface.

In our case it would have been enough, I have posted the case here

http://www.scubaboard.com/forums/accidents-incidents/284324-first-incident-free-flow.html

The case with SP MK17/S600 was after that one. It was about to free flow once we passed, as I remember, 60ft mark. We have returned to 45' mark and symptoms went away so we just stayed at that depth.

 

[Coldwater_Canuck]

In our case it would have been enough, I have posted the case here

http://www.scubaboard.com/forums/accidents-incidents/284324-first-incident-free-flow.html

The case with SP MK17/S600 was after that one. It was about to free flow once we passed, as I remember, 60ft mark. We have returned to 45' mark and symptoms went away so we just stayed at that depth.

Interesting post, that sounds like more or less a good way to handle it: breathe out of freeflowing reg to get to your buddy, each get on seperate air sources and ascend to gether (I personally probably wouldn't have swam along the bottom, but you did have a lot of air I guess)

So what happened with his tank, did you just leave it on and it emptied or did the flow stop at some point? I do wonder how long a freeflowing tank would last, I wouldn't think too long, when I hold down the purge it seems to drop pretty quick (although I guess if you were able to reach your valve you could probably turn your tank on and off to make the air last longer).

By the way, I have the same regulator as you. Why were you using a Scubapro that other dive (and how did you know it was 'about to' freeflow)? And what reg did you get for your pony?

 

[shoredivr]

FYI about water temps, check this for July. Diver's Den

 

[Coldwater_Canuck]

FYI about water temps, check this for July. Diver's Den

I've seen that, but it doesn't seem to match up with what people in this thread have been saying. 50 on a deep dive isn't bad at all, hitting 40 is getting pretty chilly.

 

[shoredivr]

from my logbook:

July 22/07 Forest City 47F, 118 ft.......Arabia 40F 108 ft

July 19/08 Forest City 40F 141ft........Niagara II 41F 83ft........Lighthouse 60F 66ft

 

[CDNScubaMoose]

By the way, what did you do in those situations? We were taught how to breathe out of a freeflowing reg, but were never taught it in the context of if it happens in the middle of a dive where you're not near the surface. Because obviously when you were past 100, that freeflow won't get you to the surface. Even at 50 or other OW depths, I don't think a freeflow would get you to the surface. You could treat it as an OOA situation, but I'm not sure if you tried to take advantage of the air that was flowing or not.

Keep in mind - it was the 2nd stage that was freeflowing, not the first stage. Most courses simulate the 1st stage freeflow which typicially resemble a jacuzzi in the face. In my situation it was the 2nd stage that wouldn't quite "shut" so it was more of steady stream of bubbles. A 2nd stage freeflow can lead to a 1st stage freeflow since the gas is constantly going through the 1st stage which means it keeps getting colder until you freeze it up.

First time - I cranked down on the knob that you use to adjust the ease of breathing until it was at the hardest breathing setting, I was patient with my breathing to give everything a chance to "warm up" and then things were fine.

Second time - I was on my way back to the block (at the end of the dive) when it started to happen. I tried the same trick as before, it worked for about 20 seconds and started again. The dive was basically over so I started to ascend up the line with my buddy right beside me. I was also on doubles so if things got worse I could shut down the offending regulator. About 60' - above the thermocline, it quit on its own.

 

[elan]

So what happened with his tank, did you just leave it on and it emptied or did the flow stop at some point? I do wonder how long a freeflowing tank would last, I wouldn't think too long, when I hold down the purge it seems to drop pretty quick (although I guess if you were able to reach your valve you could probably turn your tank on and off to make the air last longer).

The tank was less then half empty at the surface, we did not close his valve as it was much task loading at that level of experience that time. But yes it's possible to close the valve

By the way, I have the same regulator as you. Why were you using a Scubapro that other dive (and how did you know it was 'about to' freeflow)? And what reg did you get for your pony?

That was happening with my buddy's reg. I have Zeagles Flathead VI on both pony and main. He had oceanic which was not cold water when it freeflowed. He already had MK17/S600 but did not take it for the trip for some reason.
When going down at some point he started noticing that the reg was pushing air w/o control when he moved up it stopped. So if we would have got to our planned depth of 85 it would have started flowing.

He uses Sherwood Brut on his pony now.

 

[elan]

About 60' - above the thermocline, it quit on its own.

So you got the same effect we have got that time with S600. Did you lower the IP after that case ? or what IP did you have ?

 

[Coldwater_Canuck]

The tank was less then half empty at the surface, we did not close his valve as it was much task loading at that level of experience that time. But yes it's possible to close the valve

Only half empty? Did it stop freeflowing at some point?

That was happening with my buddy's reg. I have Zeagles Flathead VI on both pony and main. He had oceanic which was not cold water when it freeflowed. He already had MK17/S600 but did not take it for the trip for some reason.

Ah you actually bough a second Flathead? I'm leaning towards a Atmos Pro for the pony, also sealed and balanced (and adjustable second stage) but a fair bit cheaper (and I think lighter) than the Flathead.

When going down at some point he started noticing that the reg was pushing air w/o control when he moved up it stopped. So if we would have got to our planned depth of 85 it would have started flowing.

Good that it gave some sort of warning at least.

 

[Coldwater_Canuck]

Keep in mind - it was the 2nd stage that was freeflowing, not the first stage. Most courses simulate the 1st stage freeflow which typicially resemble a jacuzzi in the face. In my situation it was the 2nd stage that wouldn't quite "shut" so it was more of steady stream of bubbles. A 2nd stage freeflow can lead to a 1st stage freeflow since the gas is constantly going through the 1st stage which means it keeps getting colder until you freeze it up.

First time - I cranked down on the knob that you use to adjust the ease of breathing until it was at the hardest breathing setting, I was patient with my breathing to give everything a chance to "warm up" and then things were fine.

Second time - I was on my way back to the block (at the end of the dive) when it started to happen. I tried the same trick as before, it worked for about 20 seconds and started again. The dive was basically over so I started to ascend up the line with my buddy right beside me. I was also on doubles so if things got worse I could shut down the offending regulator. About 60' - above the thermocline, it quit on its own.

Good to know

But with the first vs second stage freeflow, when you hit the purge my logic would think that would be simulating a second stage freeflow (since the first stage isn't touched at all, it's just the second letting all the air out). Why is it a second stage freeflow doesn't resemble a purge?

I also realize in this discussion I should really take an equipment course when I have a chance to know what's going on "under the covers" a little better.