doubles diving, allys or steel?

[randy88k5]

I say get whatever is available and at the right price. Get lightly used tanks if you can.

However, for a specific recommendation, I would suggest getting AL80/10L with an isolation manifold. Learn on them, then progress to steels. Remove the manifold for use on the steel tanks, and use the aluminum tanks as stage bottles.

 

[Gilldiver]

The following is from Joel Silverstine a while back:

B A L A N C E ..... balance.

Much of the "dont dive steel with wetsuits" information came out of South Florida in the mid 1990s when DIR / GUE / WKPP programs were being created. Much of this had to do with diving PST 104s with 3MM wet suits .... that in and of itself is a big ole problem larger than we have room to argue over. Since they were not going to change steel tanks aluminum was the logical choice.

Steel cylinders have been in use with wetsuits much longer than aluminum cylinders have been. Go back to the beginning before alum cylinders were made for scuba.

Different steel cylinders have different buoyancy characteristics. Some are rock heavy, some are light as a feather (loosely speaking) 7, 7.25, 8" cylinders all are different and displace different amounts of water. And each diver is different in displacement as well.

Remember that a BC / Wing is not an elevator it is a "compensator" it is to compensate for the decrease in thickness of an exposure suit and the compression of the air in the wing and lungs as one goes deeper. In an ideal world all you really need is enough lift to make you 1 lbs positive and you can then swim up. But the real world does not work that way and we have to sometimes overcompensate for stability with additional ballast for control.

My favorite cylinder with a 5mm wet suit in fresh water is a Faber 95. With a 3mm a Faber 85. I can glide -- move to salt water and I will add a little weight to compensate for the salt water.

For doubles it gets a little more involved because of the weight of the bands and manifolds but still manageable.

I have found that Faber LP steel cylinders have a cleaner buoyancy swing than the X cylinders have. And when not overfilled they balance out very nicely with wet suits.

Aluminums tend to be a bit floaty and will require 8 lbs of neutralization balast to be added for just the cylinders.

Assuming the balance of the rig can be created and, we know it can the big question comes down to this.

"What is the probability that a dive wing will fail and provide zero lift?"

Since 1989 when I started to dive with wings. I have had 3 wings provide some problems in

Wing 1. Dive Rite Classic wing - 1800 dives on it developed pin hole leaks at the welding seam. (did not lose buoyancy - replaced cell)

Wing 2. Halcyon Single Wing - 20 dives on it snagged wing on piece of wreckage on the Rhone and got small hole. (Halcyon could not repair or replace - I threw it out)

Wing 3 Inflator cracked due to HP seat failure in regulator. Wing held air as hose was below the bubble level.

Dive equipment rarely fails. When it does more than 95% of the time it has to do with a maintenance issue which falls back to user issue.

Divers need to learn how to inspect equipment pre and post dive. This will lead to few if any failures. Care for equipment on boats is important as well. Keep your gear tidy. In your space and not all over the place and it will rarely if ever get damaged.

So to answer the OPs question. .... Yes you can dive steel tanks with a wet suit so long as the rig is balanced and you can swim it out should you have ZERO ability to inflate the wing. The balance is something that is based upon your size and needs and the needs of your team.

cheers
JDS

 

[DevonDiver]

....or does it not matter

 

[Mike2Fst]

Try different configurations and go with what you finds suits your needs and comfort as long as it is safe. I prefer HPS 120s sidemount with a mix of alluminum 40s and 53s as deco/stage bottles. I regularly dive with a friend who has double alluminum 80s back mount with 2 alluminum 80s for deco/stage bottles. Yes, we always debate/defend our configurations. Bottom line is that we are competent with our set ups and are also familiar with eachothers configurations in case of emergencies. Have fun and enjoy your progression in this wonderful sport.