Tobermory Dive Operations

[Coldwater_Canuck]

You are 100% right. I have seen what could have turned into a free flow it just 3 weeks ago on a second stage od Scuba Pro S600/MK17 It was just inappropriate second stage for that kind of conditions.

Huh? Isn't that a great reg?

 

[CDNScubaMoose]

I've had the "pleasure" of my S600 freeflowing twice on the Arabia (both times right around 40 degrees). I have it on a MK25 first stage but in both cases it was the second stage that started to freeflow. I have since had my technician reduce the IP.

In the great lakes - its not if you will have a freeflow but rather when it will happen.

 

[bleeb]

I looked it up and the difference is about 2 degrees, so if your regulator would freeze in 40 salt water, it would equivalently freeze in 42 fresh water: good thing to keep in mind but not a drastic difference either.

You want to be careful how literally you interpret that 2 degrees (sea water of 'normal' salinity.) One of the funny effects with salt water is brine concentration. Initially, it's not the salt and water that freezes, but just mostly the water. A little bit of the water freezes out, leaving most of the salt behind in the remaining liquid. So as more of the mixture is solidified, it's possible to get pockets of water of increasing saltiness and decreasing freezing point.

Now in a reg, I imagine the situation gets even more complicated, with different amounts of circulation at different places allowing some of that excess salt to be dumped back into the surrounding ocean, or droplets getting into 'air' parts of the reg, where they have the opportunity to completely freeze over with loosing salt, and how big a lump of ice (microscopic or not) it takes to be a problem.

BTW, I *think* that commonly referred to 2 degrees is Celsius and not Fahrenheit.

Enough scientific philosophizing for one afternoon.

 

[elan]

Huh? Isn't that a great reg?

As it turned out that S600 us not appropriate for the temps below 40. One should use G250 instead

 

[elan]

I guess the question is what do you mean by "general attitude". I certainly don't think it's bad advice, but if it was that commonplace wouldn't it make sense for the dive shops to rent them? And what about OW classes going to 60 feet?

Sorry for confusion by general attitude I mean that many people who have some experience would suggest you to have a redundant source. I have spoken to one charter early April (the water was around 40-41 in Ontario) and they told me they refuse those w/o either pony , H valve or doubles.

Honestly I have only seen OW classes done in 45F water at depth <30. If I were an instructor I would not have taken a new person to 60ft at < 40F. Way too dangerous and many things can go wrong.

I looked it up and the difference is about 2 degrees, so if your regulator would freeze in 40 salt water, it would equivalently freeze in 42 fresh water: good thing to keep in mind but not a drastic difference either.

But I'll be extra vigilante in not doing things that are more likely to freeze it (purging, breathing too much at surface, long BCD bursts, etc.).

This goes w/o saying. This is why you do not want your buddy on your octo in very cold water.

 

[bleeb]

I have spoken to one charter early April (the water was around 40-41 in Ontario) and they told me they refuse those w/o either pony , H valve or doubles.

Out of curiosity, which charter? PM if you prefer. If you got any sense from them, is that this particular charter's general policy year-round, or is it specifically during certain times of year, or for certain depths. Thanks.

 

[Coldwater_Canuck]

You want to be careful how literally you interpret that 2 degrees (sea water of 'normal' salinity.) One of the funny effects with salt water is brine concentration. Initially, it's not the salt and water that freezes, but just mostly the water. A little bit of the water freezes out, leaving most of the salt behind in the remaining liquid. So as more of the mixture is solidified, it's possible to get pockets of water of increasing saltiness and decreasing freezing point.

Now in a reg, I imagine the situation gets even more complicated, with different amounts of circulation at different places allowing some of that excess salt to be dumped back into the surrounding ocean, or droplets getting into 'air' parts of the reg, where they have the opportunity to completely freeze over with loosing salt, and how big a lump of ice (microscopic or not) it takes to be a problem.

BTW, I *think* that commonly referred to 2 degrees is Celsius and not Fahrenheit.

Enough scientific philosophizing for one afternoon.

Ya tough to know I guess if that does happen around the regs, honestly I don't understand regulator freezing enough.

And you're right about the -2 being Celsisus, dumb mistake by me.

 

[Coldwater_Canuck]

As it turned out that S600 us not appropriate for the temps below 40. One should use G250 instead

Really? Hmm. Hopefully mine is okay since the manual specifically mentions ice diving.

Sorry for confusion by general attitude I mean that many people who have some experience would suggest you to have a redundant source. I have spoken to one charter early April (the water was around 40-41 in Ontario) and they told me they refuse those w/o either pony , H valve or doubles.

Well the reason I asked is I mean in Seattle it's generally known as a "good idea" to have a pony, but plenty of people dive without them. However, reading a few different people on here, it sounds like it may be a bit more critical here.

Honestly I have only seen OW classes done in 45F water at depth <30. If I were an instructor I would not have taken a new person to 60ft at < 40F. Way too dangerous and many things can go wrong.

I thought in OW they were supposed to take you down to 60 feet (maybe I just assumed this was a requirement though).

 

[Coldwater_Canuck]

I've had the "pleasure" of my S600 freeflowing twice on the Arabia (both times right around 40 degrees). I have it on a MK25 first stage but in both cases it was the second stage that started to freeflow. I have since had my technician reduce the IP.

In the great lakes - its not if you will have a freeflow but rather when it will happen.

Hmm all these responses are starting to have some effect on me. Maybe I will put together small pony before I go. I eventually want to get a 30cf tank, but for the depths I'll be going to a 13cf should be okay (and if I want to upgrade when I start diving past 100, I would just need to spend $100 or so on a second tank, regulator would stay the same.

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.

 

[elan]

Out of curiosity, which charter? PM if you prefer. If you got any sense from them, is that this particular charter's general policy year-round, or is it specifically during certain times of year, or for certain depths. Thanks.

It was the policy during those certain times, when the water was very cold 38-41. They just mentioned it for that time only.