Why no redundancy in mainstream rec scuba?

[Storker]

I've used the debrief technique quite a lot while I was "growing together" with my regular buddy. It helped us immensely. These days, we more or less read each others' minds unless it's a couple of months since we last dived together. If it's that long ago, it takes us about one dive to get back on the same page.

 

[chrisch]

Huh. I, too, live in a cold water country and have yet to see a 1st stage freeflow (which IMO is the serious type). 2nd stage freeflows, on the surface, after the dive, are almost the rule and not the exception when the water is 4C and the air below freezing, though...

I suspect that it's because you can't buy a reg set that isn't suitable for cold water at any reputable LDS up here

More likely they are serviced properly. Regulators should not free flow, cold or not. The cold water excuse is a frequent one but my experience is just like yours, surface 2nd stage only and then stopped easily.

 

[Storker]

...and then stopped easily.

IME that works if the air is a few degrees above freezing. If it's noticeably below freezing, the typical solutions (like putting the reg back in my gob, or sticking my thumb into the opening) often aren't enough. If that happens I have to close the tank valve and wait for the 2nd to thaw up.

Another issue I've seen when the air is below freezing, is that if the 2nd stage is tuned to breathe very easily, it can develop a slow freeflow just by being exposed to sub-freezing temps. Another reason to have my backup 2nd detuned a little bit. If my primary starts to leak a smidgen, I just stick it in my mouth. Problem solved!

 

[chrisch]

IME that works if the air is a few degrees above freezing. If it's noticeably below freezing, the typical solutions (like putting the reg back in my gob, or sticking my thumb into the opening) often aren't enough. If that happens I have to close the tank valve and wait for the 2nd to thaw up.

Another issue I've seen when the air is below freezing, is that if the 2nd stage is tuned to breathe very easily, it can develop a slow freeflow just by being exposed to sub-freezing temps. Another reason to have my backup 2nd detuned a little bit. If my primary starts to leak a smidgen, I just stick it in my mouth. Problem solved!

It's colder where you are

Yes - the cracking pressure is key - easily put right. I really don't know where the idea that it should be hyper sensitive came from, but I have come across a number of service outlets that think it should be set at a pressure that really invites a free flow.

 

[dmaziuk]

Indeed. Neither would I toss my mask on a boat.

I bet that guy won't anymore either. And neither would anyone else who was there.

 

[MichaelMc]

I just wonder why a DM in training posts up that rec divers are not safe? Really?

The board has ample evidence of post training buddy failures. Many are safe, but as a group they are not reliably so if we pay attention to near misses. I don't assist with OW students. My DM training is with post AOW students. We have 100 hours of class, 10 two hour pool sessions and 12 northern California ocean dives, usually low vis working dives in kelp. They leave fairly well indoctrinated on safety.

 

[MXGratefulDiver]

Since NAUI is not a member of the RSTC, they may have an excuse. My experience was that I, or anyone in the class, would not receive certification if I did not know and practice proper buddy diving behavior in that NAUI/PADI class some time in the past.

PADI should adhere to the RSTC OW standard, a portion quoted below.

Lets face it, the majority of divers follow a DM around some tropical dive site, and the instructors that want to cut corners use that to justify short changing their students because the students will never know how poorly they were trained until they have to dive on their own, which may never happen.

Bob

That's WAY in the past, Bob ... and significantly misleading.

NAUI strongly supports the buddy system ... which is why they have no offering for solo diving. The NAUI credo specifically states that NAUI believes in the traditional concept of the buddy system.

NAUI Credo

Also, you should know that NAUI was one of the founding members of the RSTC. Subsequent politics led to their leaving the organization, but in no way do NAUI's courses offer anything less in terms of safety or quality than what is mandated by the RSTC ... in fact, by most metrics, NAUI courses exceed what the RSTC mandates.

... Bob (Grateful Diver)

 

[Bob DBF]

That's WAY in the past, Bob ... and significantly misleading.

NAUI strongly supports the buddy system ... which is why they have no offering for solo diving. The NAUI credo specifically states that NAUI believes in the traditional concept of the buddy system.

I was answering a specific statement below that buddy was not added to the statement about planning and conducting a dive.

Both NAUI and PADI state the end goal is a student should be able to independently (without supervision) plan and conduct a dive. Granted, they don't add "buddy" at the end of the statement.

My OW training was quite a while ago and although teaching buddy diving was an intergral part of my training, I have no first hand knowledge of what the NAUI standard. Since PADI belongs to RSTC, planning and conducting a dive with a buddy is explicitly stated in the RSTC standards they follow.

My OW instructor parted with PADI when they decided students certification is not to be dependant on instructor added material. He decided those standards were not adequate for the conditions of the NorCal coast and continued with NAUI alone.


Bob

 

[MargaritaMike]

Get your girlfriend diving - that is the best buddy you can have.

I tried this and my wife got really pissed off.

Cheers - M²

 

[Germie]

More likely they are serviced properly. Regulators should not free flow, cold or not. The cold water excuse is a frequent one but my experience is just like yours, surface 2nd stage only and then stopped easily.

Sometimes it has nothing to do with servicing. I never had a freeflow myself during a dive with 1 of my regs which are never serviced, or serviced by myself. Never serviced means here they are checked regularly by myself, but never be totally serviced because they are relative new. I service myself when it is needed. I own Apeks DS4, Scubapro MK17, MK19 and Aqualung Titan LX Supreme.
But I had after letting servicing the Titan by an official technician several freeflows (it was in the time I didn't know how to service myself). Every time I went back to the shop and when I thought it is now ok(a week no problems), I got a freeflow after coming from 110m/360ft depth when I switched to the EAN50. All no problem, close valve, open it to breath, close it again. But after 5-6 breaths, there was no gas coming anymore. A full cylinder, 25 dives after servicing, several freeflows before this dive, but the last 10-15 dives no freeflows anymore. We finished the dive with no other issues and problems, no stress has been there, but I went to another shop to let them look at my regulator which had worked flawlessy without servicing for about 450 dives and gave problems after servicing. They found that there was a part wrong assembled. Then I decided to follow a course to do servicing myself. So this reg was 'serviced' well, but gave problems.

Another thing is the breathing pattern of some divers. They get more freeflwos at depth in winter. And when others take the same regulators, then no problems.

I only got freeflows when I walked or jumped in the water and the regs touched the water on the purge button.If the outside temperature is just a few over freezing temperatures or below, you cannot stop the freeflow as the first stage will freeze too. The only way is to close a valve.
Some divers cannot imagine this, but it is really happen here in winter.
This is why it is adviced for sportsdivers (recreational diving) to have 2 first stages and a dual outlet valve. I will not dive with sportsdivers under ice if they don’t have this (ice diving is overhead, but a sportsdiver specialty here).

And even if you service every year or every 100 dives, some divers get salt and moisture in the first stages, some already after a few weeks or months, the first stage is then not clean inside anymore and will maybe not work properly anymore.