2 valves per tank, why?!

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I dove the Radau in Lake George this spring. At 102 feet it was 43°F. My very inexpensive Cressi AC2 unbalanced piston with a Hollis 500SE didn't have any problem. Nor did my pony with an H2Odyssey valve/1st stage and a Cressi XS2 second. On the other hand My buddy had his expensive reg freeflow as soon as we got down and we had to abort the dive. Go figure.
 
Hm. I dived in France earlier this summer. Although all the tanks had Y valves, I never noticed our guides using two single stages. I'll have to double-check my footage to be 100% sure, though. And on one of the dives, our guide was very clearly "taking charge" of another diver, since we were told that the third customer was on his first deep dive so we should just follow them and otherwise dive as an independent buddy pair as we were used to. We happily mounted our standard single tank configured regs (one primary, two secondaries) on one of the tank outputs and was never admonished that this was in any way "bad".

OTOH, this was a comfortably laidback op that let competent divers do their thing and didn't try to hand-hold anyone who didn't clearly need that.

Hi Sinterclaus. Not the first time that you are not in agreement with what I am writing. So please find hereunder, the text of the french law that rules diving in France. It is called the "code du sport" and of cours, it is in french. But I am sure that, as a smart Norvegian you will master it :)

« Art. A. 322-80. − Chaque bouteille ou ensemble de bouteilles d’un même gaz respirable est muni d’un
manomètre ou d’un système équivalent permettant d’indiquer la pression au cours de la plongée.
« En milieu naturel, chaque plongeur équipé d’un appareil à circuit ouvert est muni d’un système gonflable
au moyen de gaz comprimé lui permettant de regagner la surface et de s’y maintenir.
« En milieu naturel, chaque plongeur encadré au-delà de 20 mètres et chaque plongeur en autonomie est
muni :
« – d’un équipement de plongée permettant d’alimenter en gaz respirable un équipier sans partage
d’embout ;
« – d’équipements permettant de contrôler les caractéristiques personnelles de sa plongée et de sa remontée.
« En milieu naturel, la personne encadrant la palanquée est munie :
« – d’un équipement de plongée avec deux sorties indépendantes et deux détendeurs complets ;
« – d’un système gonflable au moyen de gaz comprimé lui permettant de regagner la surface et de s’y
maintenir ;
« – d’équipements permettant de contrôler les caractéristiques de la plongée et de la remontée de sa
palanquée.

---------- Post added July 30th, 2015 at 06:55 PM ----------

For my friends that are not Norvegian, let me translate:

En milieu naturel, la personne encadrant la palanquée est munie :
« – d’un équipement de plongée avec deux sorties indépendantes et deux détendeurs complets ;
« – d’un système gonflable au moyen de gaz comprimé lui permettant de regagner la surface et de s’y
maintenir ;
« – d’équipements permettant de contrôler les caractéristiques de la plongée et de la remontée de sa
palanquée.

In natural waters ( not in a pool)
The person that is in charge of the group of divers will have:
a scuba diving equipment with two independant exits and 2 full sets of regulators.
An inflatable system that can be inflated with compress gaz and will help him to reach the surface and maintain a positive buyancy.(A BCD)
instruments in order to measure the parameters of the dive and the ascent process.( computor or gauge and timer)
 
The Norvegian and I would like to note that the French laws/general attitudes are not representative of European diving in general. Please don't use too wide a brush when painting your impressions of diving in Europe.
---
Which reg freeflows and which doesn't is often related to which regulator was exposed to any moisture before the dive. First of all the reg needs to be completely dried since its last use or rinse. You mustn't leave gear out in the cold too long, nor in a cold car overnight, and esp. you need to keep your [moist] breath away from the reg until you are underwater. Also avoid creating any rush of air thru the reg, for instance by filling a SMB using your reg. These mistakes might be what makes a "good" cold water reg start bubbling when another reg was doing fine.
 
Hi Sinterclaus. Not the first time that you are not in agreement with what I am writing. So please find hereunder, the text of the french law that rules diving in France. It is called the "code du sport" and of cours, it is in french. But I am sure that, as a smart Norvegian you will master it :)

In natural waters ( not in a pool)
The person that is in charge of the group of divers will have:
a scuba diving equipment with two independant exits and 2 full sets of regulators.
An inflatable system that can be inflated with compress gaz and will help him to reach the surface and maintain a positive buyancy.(A BCD)
instruments in order to measure the parameters of the dive and the ascent process.( computor or gauge and timer)

I know this may be shocking to you, but I don't think he said French law was other than as you described it...just that in his experience the law was given about as much respect by French divers as any other piece of toilet paper. In other horrific news for you, many drivers don't obey posted speed limits.
 
We constantly fight against people who try to impose their high and mighty progressive elitist crap on us. That's why the US is here, for free minded people to get away from countries that have nonsensical rules.

ROFL. You need to get out of your bunker more frequently.
 
The french position is not all that unreasonable. It is not uch different that our diving practices having a second , second stage to share or use if ours fail. It appears that the dual reg idea is for overflow caused reg freeze. I would suspect that if The US was in the latatudes of the artic circle that we would also adopt such a degree of redundantcy. The only difference i see is that the frence feds have taken charge of the scuba standards where in the states they have not. I dont see the french policy as one that is intended to guarentee the one surface for every dive ratio as much as it is to maximise the odds of dive surface ratio of 1:1 by imposing a mandated backup system as it sees is necessary for the equipment dives and environment involving french homeland diving. I also see the US responce to the french position the same as most divers int he US that will say that just because the cavers use 2 regs,,,, it is retarded for non cave divers to have to follow suit.
 
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Which reg freeflows and which doesn't is often related to which regulator was exposed to any moisture before the dive. First of all the reg needs to be completely dried since its last use or rinse. You mustn't leave gear out in the cold too long, nor in a cold car overnight, and esp. you need to keep your [moist] breath away from the reg until you are underwater. Also avoid creating any rush of air thru the reg, for instance by filling a SMB using your reg. These mistakes might be what makes a "good" cold water reg start bubbling when another reg was doing fine.
Besides, I've yet to experience a free-flowing 1st stage¹. Free-flowing 2nd stages, sure. Quite a few. Particularly if you continue breathing the primary 2nd after surfacing on a cold (<4C water, <0C air) dive, then it's almost mandatory. Big deal? Nope. You dive is finished, you're at the surface with air in your BCD. Just a minor nuisance. Have someone close your tank valve, and all is good. If it happens underwater (never experienced it, but sometimes sh!t happens), any OW certified diver should be able to switch to their backup or just sip from the freeflowing reg and surface. Unless, of course, we're talking about tec diving.



¹ Which just may be due to the fact that I've also yet to see a piston-type 1st stage, every 1st I've ever seen here in cold water country have been the diaphragm type
 
i don't think padi, or any other major training organisation for that matter, allows people to dive below 40m with only recreational training. As for the dual first stages, most people don't bring their own tank when they travel. Renting a second first stage could be a little extra, but doubtfully a deal breaker if you have already invested so much in the trip. And unless you have to have two second stages on both first stages you can just have your octo in the second one and have the same amount of hoses to deal with. In fact, i find this place pretty interesting right now and really hope that canyondreamer51 will write a report on it.

bsac, cmas, saa
 
Statement: don't think padi, or any other major training organisation for that matter, allows people to dive below 40m with only recreational training.
Reply: bsac, cmas, saa

In Finland CMAS3 is to 40m. CMAS4 is a lifetime achievements & contributions recognition, not an actual cert level. Divers can and do of course dive according to their own judgement, but the cert is officially to (not below) 40m.
 
bsac, cmas, saa
Moreover, instead of just a list of acronyms, I would greatly appreciate an actual quote or reference to one of these training agencies' recreational manuals stating that the training will allow a diver to dive to depths of more than 40m (or equivalent in feet). In no way do I consider myself infallible and if an agency out there really promotes recreational diving below 40m I'd be interested to know.
 
https://www.shearwater.com/products/teric/

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