IndigoBlue
Contributor
Choosing a tank is often a bargain hunting proposition. That is why most divers first buy aluminum tanks. They cost less than steel, in the short term.
Divers who normally do not buy an aluminum tank, often buy a used steel 72 tank, because they seem to last forever, and they are also inexpensive as well. In the very long term, these are the best bargains out there.
SeaJay's analysis is technically correct. However not all dives are technical.
If you always dive shallower than 50 ft, and there is a 50 ft bottom under you, then any failure scenario should be able to be resolved by you ditching your weights and EBA back to the surface. Its not like you are diving to 330 ft on deco.
With a steel tank, you have less weight on your weightbelt. So my first suggestion would be to look for any bargain sales in your area for steel 72s.
If you are diving warm water as well, then an aluminum tank also becomes more feasible, since warm water does not require a lot of lead weighting to begin with. Adding 6 more pounds of lead to offset the tank is not a problem in warm water.
If you dive deeper than 50 ft, then everything SeaJay said is right on. But there are different ways to prepare for the failure contingencies as well. Buddy diving with each of you having a wing/bladder large enough to lift you both is one option. That is why instructors often wear larger capacity B/Cs, to catch and hold that run-away AOW student on the deep dive activity.
As long as you have sufficient ditchable weight, you can EBA in the event of a major B/C failure. With a thick wetsuit, you simply need more ditchable weight than with a drysuit. A lot more.
So your answer is going to depend on your exposure suit as well as your B/C. Generally speaking, an aluminum 80 will be your best bet, with a steel 72 possibly a good choice instead.
Divers who normally do not buy an aluminum tank, often buy a used steel 72 tank, because they seem to last forever, and they are also inexpensive as well. In the very long term, these are the best bargains out there.
SeaJay's analysis is technically correct. However not all dives are technical.
If you always dive shallower than 50 ft, and there is a 50 ft bottom under you, then any failure scenario should be able to be resolved by you ditching your weights and EBA back to the surface. Its not like you are diving to 330 ft on deco.
With a steel tank, you have less weight on your weightbelt. So my first suggestion would be to look for any bargain sales in your area for steel 72s.
If you are diving warm water as well, then an aluminum tank also becomes more feasible, since warm water does not require a lot of lead weighting to begin with. Adding 6 more pounds of lead to offset the tank is not a problem in warm water.
If you dive deeper than 50 ft, then everything SeaJay said is right on. But there are different ways to prepare for the failure contingencies as well. Buddy diving with each of you having a wing/bladder large enough to lift you both is one option. That is why instructors often wear larger capacity B/Cs, to catch and hold that run-away AOW student on the deep dive activity.
As long as you have sufficient ditchable weight, you can EBA in the event of a major B/C failure. With a thick wetsuit, you simply need more ditchable weight than with a drysuit. A lot more.
So your answer is going to depend on your exposure suit as well as your B/C. Generally speaking, an aluminum 80 will be your best bet, with a steel 72 possibly a good choice instead.