Are single tanks used for wreck penetration? (+)

[GDI]

:doctor: Singles and Wreck Diving

Many will say you should not do penetration unless wearing doubles. I always wear doubles. As a cave instructor I must tell you that in cavern and intro to cave a single may also be worn provided you have the correct set up. Cavern can be done in open water gear with some adjustments. Cavern and Wreck are very similar ( I also teach wreck) The issue of single verses doubles really gets down to air management 1/3's. If you opt to wear singles make sure you plan correctly and are confiqured correctly. H valve or Y valve, two regs, light, reels. lone arrows and training

 

[SHPWRCKDVR]

As a fly on the wall, I just wanted to thank everyone for all the good information posted in this forum. As a diver who loves to dive on wrecks, I enjoy learning from my peers. Once again thankyou for all the great information!

I think it was from an old Benny Hill episode that said "Learning all the time!"

 

[patmandu]

I've had personal experience with a tank neck o-ring extruding. A few years ago during a trimix course, the left tank on my doubles extruded with an extremely loud 'bang' and hiss. Luckily, I had just stood up, put on my stage bottle and was walking towards the swim platform when it happened. I'm glad it didn't wait 5 or 10 minutes before it went, as I would have been in 'mid dive'.

The tanks were AL80's, Halcyon Manifold, and Highland Millworks bands (all great equipment and appeared well cared for).

Needless to say, I sat on the boat dry that day.

It does happen, and it can give you a good scare when they go 'off' next to your ear.

 

[ElectricZombie]

I would not use a single for real wreck penetration. I dive doubles 99% of the time anyway. You never need a double bladder wing if you're not overweighted.

 

[Genesis]

... but I will also tell you that I have done it and I'm still here

I DID have a buddy with a long hose with me, a pony, and dove thirds; if either of us had a catastrophic failure we had the other to get out on PLUS a 19cf pony.

Having now acquired several sets of "light" doubles (72s) I prefer them by far - they're not much heavier, all-up, than a big single and a pony and are a LOT safer.

 

[Hoya97]

Yeah, I think I just had one in fact.

I went out to teach a class on their first Open Water dive training session. The first dive went well, no problems. I swapped out the tank that I had used for the first dive and threw on another tank (both are my tanks, not the shops). It was noticably lighter but I was stunned to discover it was totally and completely (read: 0 PSI) empty! ! !

Okay, I keep an extra because students (NEVER THE INSTRUCTOR) need an extra tank. After muttering something about the bozo who filled my tank, I completed the dives without further problem.

Next day, I went to the shop and told them the puppy was totally empty. Yeah Yeah Yeah, got the expected lecture from the top dog instructor about letting tanks run dry.... SIGH.

The following day I went in to pick up my tanks. The tank in question felt really light again. I asked for a guage and discovered that it was at 1,500 PSI. I muttered again about the same bozo and asked for a top off. When it was done, the person filling the tank said that I had a leak.

I went over to the tank, thinking that I blew a valve or something. Much to my surprise, there was a slight hissing coming, not from the valve, but from the neck and valve met. Put some water on the area and sure enough, that's where it was bubbling from!

Asked the shop to 'please fix the problem' and picked it up about two days later. The repair person said that it was the seat alright.

So I guess the story is that it does happen and it is a slow, almost unnoticable leak and it's an easy fix. I've been diving for 30 years and it's never happened before so I doubt it occurs frequently.

Just thought I would share the experience with you folks. Not ment to support one side or the other side of the discussion.

 

[MASS-Diver]

Before I had my doubles, I did some penetration on shallow wrecks using a single hp120 and a slinging a 40cu pony. At the time I thought it was a decent righ (espically for 40' of water) and sometimes doubles are tough to lug on a small boat or along a rocky shore line to a near by wreck, but, in general I would say don't go into an overhead env. without doubles and the ability to close your valves well.

As far as dives to 100' plus, I would now get nervous doing them on singles even w/out penetration.

 

[BrianM]

What about losing a burst disc??? I just got the shock of a lifetime in Monterey a few weeks ago....I was putting my reg on my tank and the tank next to mine blew the disc for no reason at all.....of course this was right as I was turning on my tank valve so my life flashed before my eyes and I almost had to shovel out my wetsuit :wacko: but seriously......the temp was a cool 61 degrees and cloudy with a breeze.....the tank had just been sitting, not filled that day at all.

So I guess my point is could it happen underwater too? Has anyone ever seen a disc blow underwater?


Brian

 

[MASS-Diver]

Nope, I don't know anyone who has had one go underwater, but, I know several people that have had one blow at the fill station.

A lot of people double them up.

 

[flw]

MASS-Diver once bubbled...
Nope, I don't know anyone who has had one go underwater, but, I know several people that have had one blow at the fill station.

A lot of people double them up.

No-one outside of the US uses them at all, and we're not having any problems without them

f