Diving with a 15 litre tank.

[DuboisP]

my primary tank is a 15L steel.
very common in Europa.

 

[DaleC]

A German shepherd

Figures. All the cool kids are packin Dachshunds these days.

 

[Ottoman Diver]

Figures. All the cool kids are packin Dachshunds these days.

Call me old school I'm happy with my old proven gear.

 

[String]

For normal scuba it seems to be normal to dive with 11.5litre ally tanks or 12.0 Litre steels.
For boat diving I'm wondering why a diver wouldn't dive with a 15 litre tank.
Wouldn't that offer a lot of the advantages of a pony bottle?

Why would you do the dive if you don't need the gas? Why is a boat different to shore?

The 15l tanks (whether its a REAL 15l tank or the 100cf ft things that companies claim to customers are 15l) are physically bigger, physically heavier and dont offer any advantage of a pony. A pony is a redundant air source designed solely to be used if the main gas supply stops working. A bigger tank can't fulfil that role as it has no redundant regulators or gas supply.

 

[Krazytomdiver]

As a dive guide, 15L tanks are nothing but a hassle on a boat. They do not fit the standand tank holders on the boat which means you have to store them on the deck,always in the way,adjusting tank straps on some BCD"s is difficult,AND number one...they are heavy! They are just a substiution for poor gas management. Next we will be converting 55gal drums into dive tanks. "May I supersize your tank for you mister?"

"living life without a hard bottom"
KT

 

[shoredivr]

Many DCs will put an extra $5 or so on to the price of a 15. They're also right bastards for the crew to load. Steels are even worse!

Around here steels are pretty common, boats rarely have divemasters, and you load your own gear on the boat, including tanks.

 

[Ottoman Diver]

They are just a substiution for poor gas management.

The only reason I use to use 15L tank was because I was just starting to dive and had bad SAC and I did not want to reduce the dive time of my buddy diving a 12 L. However Now I don't even think about diving a 15L tank. I'm happy with my 12

 

[cloudflint]

They are just a substiution for poor gas management.

For me its more about getting more bottom time, particularly in the 10-20 metre range. On a 12 litre cylinder in that range il hit rock bottom before i run out of time, so diving on a 15 lets me stay down longer.

 

[beester]

As a dive guide, 15L tanks are nothing but a hassle on a boat. They do not fit the standand tank holders on the boat which means you have to store them on the deck,always in the way,adjusting tank straps on some BCD"s is difficult,AND number one...they are heavy! They are just a substiution for poor gas management. Next we will be converting 55gal drums into dive tanks. "May I supersize your tank for you mister?"

"living life without a hard bottom"
KT

Oh man I love your overgeneralisations... As a diveguide (you seem to start all your posts like this) you should maybe broaden your diving experience beyond tropical reefs. Check out some dives in non tropical water before making such broad assumptions.

If you were doing a dive on wrecks in the north sea, along the british coast, French riviera, Norway, Germany... you'd probably be unable to count all the divers using steel 15L tanks. Next to double 12 liters and double 10 liters I also have a couple of double valved 15 liters.

As I try to focus on good trim and streamlining I obviously do dive alot with doubles, but also a 15 liter steel tank can be dived in very good trim without any issues. (see pic below)




Regarding gas management or redundancy. Were I live every 15 L tank you'll see has two redundant valves, and separated regulators. So with a free flow you can in fact close off 1 side. I also wouldn't want to feed every diver I've seen diving on deep wrecks (40-60m range) with a 15 liter like this. Is this responsible, well this depends on your viewpoint (mine is you shouldn't do dives like that with a mono tank, even a big one).

 

[String]

Around here steels are pretty common, boats rarely have divemasters, and you load your own gear on the boat, including tanks.

Depends which steels. For some reason the american steel tanks are HUGE, very heavy and still only good for about 210 bar.

Europe/rest of world a steel tank is lighter than the same capacity aluminium tank (thinner walls), physically smaller (doesnt need t be as big) and holds a higher pressure (232 or 300 bar).

A steel 12.2l dumpy is 2kg lighter and smaller than an aluminium 80 (what places tend to call a 12l even though it isnt) and holds 10% more gas.