No wing on a backplate harness and tank for Caribbean shallow diving -how does this work?

[Angelo Farina]

Hmmm. If the diver is running both a primary 2nd stage and a secondary 2nd stage on his single 1st stage, then doesn't he/she have an "octopus" regulator?

Maybe a reg requires more hoses (e.g., a LP BC power inflator hose and a HP SPG hose) to be considered an "octopus" reg. (I really don't know...)

rx7diver

I did also dive this way in some occasion. Just a single second stage, no alternate source.
For shallow diving well within NDL, with a reliable buddy, it is still reasonably safe: at any minor inconvenience you just ascend.
From less than 10m depth, in warm clear water, it is simple.

 

[rongoodman]

Hmmm. If the diver is running both a primary 2nd stage and a secondary 2nd stage on his single 1st stage, then doesn't he/she have an "octopus" regulator?

From the context I assume by "primary" he meant first stage. So this guy had no way of donating gas, and no way of knowing he much gas he had left. I'm surprised the crew let him into the water with their other customers. "shallow diving well within NDL, with a reliable buddy" does not necessarily describe diving off a liveaboard with a group you have just met at sites like Cocos Island or Palau.

 

[nihildriven]

Hmmm. If the diver is running both a primary 2nd stage and a secondary 2nd stage on his single 1st stage, then doesn't he/she have an "octopus" regulator?

Maybe a reg requires more hoses (e.g., a LP BC power inflator hose and a HP SPG hose) to be considered an "octopus" reg. (I really don't know...)

rx7diver

I misspoke. She had a 1st stage and a single second stage and an lp hose. No spg, no air cell, no power inflator, no octo or alternate second stage.

 

[Bob DBF]

Taking minimal to the max is a whole thing. I saw someone on a very popular liveaboard diving a plastic backpack with a reg that consisted only of the primary, a single lp hose, and a single secondary. No octo, no spg, no inflator. Having met them, I think that if they ran out of air under water, they’d be like “it finally ends, thank god” followed shortly thereafter by “oh **** what about my cat?”

That's how I learned to dive, with an unbalanced reg one can tell when the air is getting low and you should ascend, although a j-valve is better. Also, once you dive enough you get good at estimating when to surface.

Hmmm. If the diver is running both a primary 2nd stage and a secondary 2nd stage on his single 1st stage, then doesn't he/she have an "octopus" regulator?

Maybe a reg requires more hoses (e.g., a LP BC power inflator hose and a HP SPG hose) to be considered an "octopus" reg. (I really don't know...)

rx7diver

Initially the reg set only had one hose to the second stage, as a BC inflator hose, spg hose, and alternate second were added, the reg set was called an octopus. I have no idea when, after 1982, the alternate 2nd stage started being called an octopus, or why, since it makes no sense.

 

[rx7diver]

@Bob DBF,

My earlier post piqued my curiosity. I just checked an old scuba textbook (Robert R. Springer's "Skin & Scuba Diver's Digest", copyright MCMLXXV = 1975). The textbook pictures (p. 12) what it refers to as an "octopus rig" consisting of a Dacor 1st stage with two Dacor 2nd stages, the "additional second stage unit with a 13-inch longer auxiliary hose marked with bright, florescent yellow stripes for instant recognition underwater."

So, evidently, (1) it is the addition of (only) a second 2nd stage that makes a regulator an "octopus" regulator, and (2) the term "octopus" was introduced in 1975 or somewhat earlier.

rx7diver

P.S.: The old textbook cited above belonged to the physician who administered my scuba physical (in 1986) required for my university open water scuba course. His widow gifted me his textbook when he passed away a few years ago.

 

[Bob DBF]

So, evidently, (1) it is the addition of (only) a second 2nd stage that makes a regulator an "octopus" regulator, and (2) the term "octopus" was introduced in 1975 or somewhat earlier.

Yes the term started early, when hoses were added, but referred to the reg set, not the additional second stage itself, which is now the common usage.

 

[Island23]

Tank Harness. Control buoyancy, with lungs. Your SAC & RMV will increase, likely rocket through the roof. Mine went off the charts & I'm trained to tread for 2 hrs. I put-on 4 lbs. In the Caribe, I have over 3500 days from Puerto Rico to Bermuda. I single 80s, 40s, 19s & 13s, don't double though. I would still use a BCD. Wear a snorkeling vest, there are sharks out-there & if you tire you have to swim to avoid rock walls or get back. I don't solo in the Caribe, unless it's a beach & -30 ft, with a harness. I had a Navy guy loose a hand to a shark, at age 21. He got out & still has a missing hand for life. Now, he can't pull a trigger or swim.

 

[shark_za]

I have done over half my diving with only a backpack, I even went one second stage and transmitter for a bit. But you get to a point of diminishing returns.
Even deeper drift diving for sharks I prefer the backpack. I would use large Gara fins to be as free as when I was while spearfishing.
But this all changes now that my daughters are both qualified and I am diving with them and my wife a lot.
I have an octo again and I'm moving to a tech backpack with wing, some pockets with SMB. etc.
Heck Im even getting booties again to wear my open heel fins.
I like that its very easy to do a kit check, not many buckles or clips, just check air and jam the octo somewhere. Easy to flip on while kitting up on the boat.

 

[jale]

Hi
I mainly dive without a bcd as if you are properly weighted, your lungs are more than enough to support the changes.
And no, your rmv doesn't increase as you are more streamlined and more efficient.
S80 with a S40, single S80, 10L steel with 3min or 5min wet suit.
Even SM and FM RB with a S80 dilout and a small alu oxy tank, bcd is not needed
Of course, some body types may make the exercise more or less difficult

 

[Angelo Farina]

Tank Harness. Control buoyancy, with lungs. Your SAC & RMV will increase, likely rocket through the roof. Mine went off the charts & I'm trained to tread for 2 hrs. I put-on 4 lbs. In the Caribe, I have over 3500 days from Puerto Rico to Bermuda. I single 80s, 40s, 19s & 13s, don't double though. I would still use a BCD.

Currently my SAC increased when I started to use a BCD.
Diving without a BCD makes you very streamlined and forces you to be properly weighted, so you swim through water which much less effort than dragging a bulky BCD and wasting air inflating and deflating it.