Recreational Scuba Deco Diving

[Celt]

But the topic here is open water recreational dives, at rec depths (50m max according to my Cmas cert) where you simply stay at bottom a few minutes more than the standard NDL time.

Personally rec. and tec. are just words. But after how many minutes does a 50 meter rec dive became a tec dive.

 

[rx7diver]

Problem with two independent tanks in sidemount is that you do not have a manifold. So if one reg fails, it becomes quite tricky to recover the gas trapped in that tank...

I actually see this as being an advantage. At no time is your entire air supply at risk. Like when using back-mounted independent doubles, you plan your dive to be able to safely return from the farthest point in the dive, on only a single cylinder if necessary. And at no time are you relying on a stand-by system. Extremely safe, IMHO. (Although I don't dive side-mount.)

rx7diver

 

[lermontov]

Problem with two independent tanks in sidemount is that you do not have a manifold. So if one reg fails, it becomes quite tricky to recover the gas trapped in that tank...
And if it is the tank connected with your BCD you have to orally inflate it.

not quite- unless you mean 1st stage the gas is still available if your reg fails the LP hose is still working for your BCD and you can feather the valve easily in sidemount
and if your following correct reg switching you should alway have enough gas to complete the dive unless your diving beyond your reserves (reserves being deco and ascent allowances)

 

[Celt]

I actually see this as being an advantage. At no time is your entire air supply at risk. Like when using independent doubles, you plan your dive to be able to safely return from the farthest point in the dive, on only a single cylinder if necessary. And at no time are you relying on a stand-by system. Extremely safe, IMHO. (Although I don't dive side-mount.)

A failure in side mount you shut down and call the dive using the other reg

 

[happy-diver]

Personally rec. and tec. are just words.

How right is this!

It used to be DIVING with one tank or two accompanied by the required amount of brain-o-bytes

Now everything is a #@%$&!# production

and look at what "they" monetarily make you give

Heaven on Earth is Shore Diving with your Garage Sale Gear

 

[PfcAJ]

not quite- unless you mean 1st stage the gas is still available if your reg fails the LP hose is still working for your BCD and you can feather the valve easily in sidemount
and if your following correct reg switching you should alway have enough gas to complete the dive unless your diving beyond your reserves (reserves being deco and ascent allowances)

Feathering the valve only gives you access to that gas for a very narrow set of failures.

Hose failure? Ripped diaphragm? You’re not getting that gas.

That’s a big disadvantage.

 

[Celt]

Feathering the valve only gives you access to that gas for a very narrow set of failures.

Hose failure? Ripped diaphragm? You’re not getting that gas.

That’s a big disadvantage.

What failure completed shuts down a reg. If it’s a no deco dive return to the surface on the other tank. If it’s a deco dive you only have to get to the first stop where you’re switching to deco gas anyway. You’re going to cut the dive when the failure happens, worst case swap the regs. at the deco stop. It takes me 1.2 minutes. Practice when you’re on deco gas.

 

[KenGordon]

Personally rec. and tec. are just words. But after how many minutes does a 50 meter rec dive became a tec dive.

I am more concerned about a so called “recreational” dive between 30 and 40m ending badly. These are serious depths where there is no room for getting things wrong in the event of a problem. This is why a gradual approach doing plenty of shallower dives that give an opportunity to face some issues is essential before taking on more serious dives.

 

[Angelo Farina]

But it is NOT the standard way of diving today. We now dive safer.

I entirely agree that the general adoption of SPG, BCD and computers increased safety significantly!
Same for the modern twins with a separation manifold, far better and safer than the old valves which did keep the twins permanently interconnected.
I am not advocating that the old way was better. Progress gave us new tools, why not getting benefit from them?
What I do not understand is why the double valve on a single tank were removed in certain part of the world. Or perhaps in US you never had them?
This could explain many things, such as the adoption of the octopus instead of the second indipendent reg, which was the standard setup here in Europe.
So, from our point of view, some modern inventions were good for safety.
But the removal of the second valve and second independent reg, replaced by just an octopus, has not been perceived as something going in the direction of increased safety...

 

[Celt]

I am more concerned about a so called “recreational” dive between 30 and 40m ending badly. These are serious depths where there is no room for getting things wrong in the event of a problem. This is why a gradual approach doing plenty of shallower dives that give an opportunity to face some issues is essential before taking on more serious dives.

For me the very idea that you can dive in a week or two if you call it rec. diving is crazy. I must be slow or something because it took me years to learn and I’m still learning, and I trained with commercial divers out of Fort Bovisand