Deep Diving 108 feet w/ a single AL 80 (Air.) No redundancy.

[d^2b]

I've been to 108' on a single aluminum 80, never for more than a few minutes as part of a planned multilevel dive. Certainly I had 1500 psi when I started to ascend, but surfacing with 1500 psi seems a little over cautious. Maybe I misunderstood the original framing being about square profile dives; that I don't have much experience with.

 

[OTF]

I've done the Poling on air al80s several times. Much prefer 120s of EAN32 with a pony, or doubles now. I guess I would do it again on a single 80 but I'd much rather have more gas for both enjoyment and safety.

The Chester Poling is easier and shallower than most comparable wrecks in the area, one can enjoy the wreck without breaking 80' depth, but I still treat it as a "serious" dive and take extra precautions, like having O2 on the boat and sometimes clipping an extra deco bottle to the line.

The thing for non-local people to understand about the Poling is that diving here is nothing like diving to 100ft in the tropics. I'd do that (and deeper) on a single 80 without a second thought. Depending on the day the waters off Gloucester can be very cold, very dark, with low visibility and sometimes entanglement hazards, rough seas, or danger-close boat traffic on the surface. You physically offgas slower in the cold, you're in more complex restrictive exposure suits, it "feels" deeper and narcosis happens sooner. All reasons to plan more conservatively on northeast wrecks.

The Poling stern is a phenomenal dive though. It's intact, penetrable, relatively easy, and has lots of nice marine life. Convenient location too.

The bow half is upside down in deeper, muddier water and by all accounts I've heard not worth diving.

 

[drbill]

Conditions in SoCal are probably much different than the dive you are referring to. I've done many dives here and in tropical waters in the 100-110 fsw range on a single 80. However I wouldn't recommend that for a relatively new diver doing a dive for their AOW cert. When diving deeper than that, I carry a pony bottle. I've done many dives to 180-200 fsw on an HP120 with a pony as well.

 

[Boston Breakwater]

I've done the Poling on air al80s several times. Much prefer 120s of EAN32 with a pony, or doubles now. I guess I would do it again on a single 80 but I'd much rather have more gas for both enjoyment and safety.

The Chester Poling is easier and shallower than most comparable wrecks in the area, one can enjoy the wreck without breaking 80' depth, but I still treat it as a "serious" dive and take extra precautions, like having O2 on the boat and sometimes clipping an extra deco bottle to the line.

The thing for non-local people to understand about the Poling is that diving here is nothing like diving to 100ft in the tropics. I'd do that (and deeper) on a single 80 without a second thought. Depending on the day the waters off Gloucester can be very cold, very dark, with low visibility and sometimes entanglement hazards, rough seas, or danger-close boat traffic on the surface. You physically offgas slower in the cold, you're in more complex restrictive exposure suits, it "feels" deeper and narcosis happens sooner. All reasons to plan more conservatively on northeast wrecks.

The Poling stern is a phenomenal dive though. It's intact, penetrable, relatively easy, and has lots of nice marine life. Convenient location too.

The bow half is upside down in deeper, muddier water and by all accounts I've heard not worth diving.

Hello. I appreciate your approach. The Poling (Stern.) is most certainly an advanced dive.
I have approximately 20 dives on the bow.
It's actually where my deepest dive was at 186 fsw. The bow is turtled, and there are no entry points. You used to be able to see the wheelhouse in the sand. It's actually extremely difficult to anchor off. The water is cold, and dark. The visibility is "Poor." to say the least. Not for the faint of heart. I was fortunate, or unfortunate (Depending on perspective.) to meet a group of divers, that were diving the Andrea Doria on a regular basis, my Open Water Instructor was one of them. They were comfortable with my skill level, and I was comfortable putting my life in their hands. Two of them are well known divers....I don't drop names, trying to be somebody.
I, to this day consider it "Informal Training." although it was an introduction to decompression diving. I did not follow the "Technical." path.
The dive is, in many aspects dangerous. It was a training site for years. I don't know if anyone uses it nowadays. In my opinion, there is no good reason to dive the bow.
Back to my O.P. I still will not dive the stern on air, with an aluminum 80 with no redundancy.
Cheers.

 

[Jack Hammer]

Would I dive deeper than 100'/30m on a single al80 these days, probably not. Have I done it in the past, absolutely. Do I generally think it's a good idea and would I recommend others do it, definately not.

Conditions, locale, experience, among others play a big role in decision making.

 

[Ayisha]

...The thing for non-local people to understand about the Poling is that diving here is nothing like diving to 100ft in the tropics. I'd do that (and deeper) on a single 80 without a second thought. Depending on the day the waters off Gloucester can be very cold, very dark, with low visibility and sometimes entanglement hazards, rough seas, or danger-close boat traffic on the surface. You physically offgas slower in the cold, you're in more complex restrictive exposure suits, it "feels" deeper and narcosis happens sooner. All reasons to plan more conservatively on northeast wrecks...

I didn't answer the original question because it seemed like one would need local knowledge of the conditions/potential hazards to make an informed decision, and your post makes that clear.

I personally wouldn't plan that particular dive with only an 80 cf without redundancy, EANx preferred, and I would use a pragmatic minimum deco profile.

 

[Storker]

I always thought it was insane????

Let me take a moment to convert that to metric.

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Ok. 108' is just a smidgen more than 30 meters. I've been to 30-ish meters on a single tank rig several times. Although with a 10L 300 bar tank, which is somewhere around 90-100 cubic feet.

It's quite doable as long as you follow proper min gas calculations, and for my rig and for me, min gas time fits pretty well with my NDL on air (about 20 minutes @ 30m). With an 80, your min gas time should be some 20% lower, so quite doable and definitely not insane. As long as you watch your gas.

 

[Storker]

Been diving since 1985, been deeper than that on an AL80, and sitting here at 70 years old, waiting to do it again.

Survivor bias.

 

[Akimbo]

Been diving since 1985, been deeper than that on an AL80, and sitting here at 70 years old, waiting to do it again.

Survivor bias.

I concur, until a means of recovering from a total gas supply failure is indicated. Depending on your buddy's octo is one option if there is adequate gas onboard. I did quite a number of mini-cave dives in Palau with large guided dive groups where the swarm of divers around you was the redundancy. Same with wreck penetration dives in Truk. Only about half of us were packing doubles or bailout bottles.

We can (and probably will) debate the relative merits of these options but we can't deny that they work the vast majority of the time. Conditions also matter. Gin-clear warm water and very experienced baby-sitters/DMs guiding a boat load of divers improves the odds over cold and turbid conditions with a single buddy.

Safe diving comes down to taking well-informed calculated risks.

 

[Storker]

Gin-clear warm water and very experienced baby-sitters/DMs guiding a boat load of divers improves the odds over cold and turbid conditions with a single buddy.

Being a proper and competent independent diver (I believe there's even an ISO standard for that, doesn't PADI OWD claim to fulfill that standard?) improves the odds even more. Without the need to be hand-held or babysat.