82 replies to this topic

[peterbj7]

Are these 232bar tanks or 300bar?

232's, all of them. Getting 300's filled is a nightmare.

[peterbj7]

Have you dived the Britannic, Trace?

No, I haven't. I would love to explore that wreck though someday; especially because it's off Greece. My GUE instructors Andrew Georgitsis and Bob Sherwood dove the Britannic when GUE did the documentary for either the History Channel or the Discovery Channel.

For an example of why divers would require large capacity cylinders for ocean diving, I used the gas plan of Nick Hope's 1998 Britannic expedition to demonstrate for Perrone a possible extreme open circuit dive.

Have you done it, Peter?

~ Trace

No. Friends of mine have been there a couple of times, the first time on O/C, the second on CCRs. Sounds a great wreck, but I'll have to wait until I'm clear of Belize before I (maybe!) try that.

[Geek]

Diverbrian,

It sounds like you and I are agreed that any overhead dive, including deco, is a "rule of thirds" dive according to the training we received. By implication, since AL80s actually carry something less than 150 cf in a set of doubles, any deco dive where you are going to use more than 100 cf of back gas, is going to put you into larger tanks. How large is a function of personal SAC rate and the nature of the dive.

In each of our respective locales, the type of diver doing overhead diving is going to gravitate toward steel tanks of 100 cf or more. He is going to be in a drysuit, and his wing should have enought lift to bring him up in a flooded drysuit.

I find a roughly 50 lb lift BC will bring me up, even in a flooded suit, but it does so slowly and I'll be using the full capacity of the wing. On the other hand, my decidedly non-DIR bungied OMS 100 lb wing will send me up and down like an elevator. Since nothing indicates that one should actually need that much lift, my spin has been that the capacities of wings are less than advertised, and you really need to try out a wing and see how it feels to decide whether it is something that has the sort of lift you would be comfortable with.

With single tank diving, even with steel tanks, I find that approximately 50 lbs. is plenty. The OMS 100 lb wing is overkill, but it works.

What has your experience been with various wings? You may have stated it earlier, but I missed it when we shifted into the tank discussion.

[Diverbrian]

Diverbrian,

It sounds like you and I are agreed that any overhead dive, including deco, is a "rule of thirds" dive according to the training we received. By implication, since AL80s actually carry something less than 150 cf in a set of doubles, any deco dive where you are going to use more than 100 cf of back gas, is going to put you into larger tanks. How large is a function of personal SAC rate and the nature of the dive.

In each of our respective locales, the type of diver doing overhead diving is going to gravitate toward steel tanks of 100 cf or more. He is going to be in a drysuit, and his wing should have enought lift to bring him up in a flooded drysuit.

I find a roughly 50 lb lift BC will bring me up, even in a flooded suit, but it does so slowly and I'll be using the full capacity of the wing. On the other hand, my decidedly non-DIR bungied OMS 100 lb wing will send me up and down like an elevator. Since nothing indicates that one should actually need that much lift, my spin has been that the capacities of wings are less than advertised, and you really need to try out a wing and see how it feels to decide whether it is something that has the sort of lift you would be comfortable with.

With single tank diving, even with steel tanks, I find that approximately 50 lbs. is plenty. The OMS 100 lb wing is overkill, but it works.

What has your experience been with various wings? You may have stated it earlier, but I missed it when we shifted into the tank discussion.

I have had no lift problems using a Dive Rite Classic Wing rated at 55 pounds. It feels perfect to me . For singles, typically a 120 with H-Valve and one deco bottle, I use a Venture Wing which I believe is rated for 35 pounds of lift and it will get sluggish once I add weight beyond the HP120.

That indicates to me with a single and deco bottle, I may wind up swimming up my gear in the event of a drysuit flood. But with a single tank that isn't a huge issue. I won't have any major deco to do with that little bit of gas and as I get shallower my lungs will become much more effective.

I have never had any real chance or need to look at other wings. I didn't look at getting the Venture Wing until I moved completely away from my jacket bc and went to a BP/W for single tanks as well. I have helped people with the bungeed wings, but I didn't like adjusting the bungees. Apparently, once the bungees got adjusted, those divers love their wings as well. It just takes a few more dives to get that adjustment made.

[Geek]

Diverbrian,

It sounds like you and I are agreed that any overhead dive, including deco, is a "rule of thirds" dive according to the training we received. By implication, since AL80s actually carry something less than 150 cf in a set of doubles, any deco dive where you are going to use more than 100 cf of back gas, is going to put you into larger tanks. How large is a function of personal SAC rate and the nature of the dive.

In each of our respective locales, the type of diver doing overhead diving is going to gravitate toward steel tanks of 100 cf or more. He is going to be in a drysuit, and his wing should have enought lift to bring him up in a flooded drysuit.

I find a roughly 50 lb lift BC will bring me up, even in a flooded suit, but it does so slowly and I'll be using the full capacity of the wing. On the other hand, my decidedly non-DIR bungied OMS 100 lb wing will send me up and down like an elevator. Since nothing indicates that one should actually need that much lift, my spin has been that the capacities of wings are less than advertised, and you really need to try out a wing and see how it feels to decide whether it is something that has the sort of lift you would be comfortable with.

With single tank diving, even with steel tanks, I find that approximately 50 lbs. is plenty. The OMS 100 lb wing is overkill, but it works.

What has your experience been with various wings? You may have stated it earlier, but I missed it when we shifted into the tank discussion.

I have had no lift problems using a Dive Rite Classic Wing rated at 55 pounds. It feels perfect to me . For singles, typically a 120 with H-Valve and one deco bottle, I use a Venture Wing which I believe is rated for 35 pounds of lift and it will get sluggish once I add weight beyond the HP120.

That indicates to me with a single and deco bottle, I may wind up swimming up my gear in the event of a drysuit flood. But with a single tank that isn't a huge issue. I won't have any major deco to do with that little bit of gas and as I get shallower my lungs will become much more effective.

I have never had any real chance or need to look at other wings. I didn't look at getting the Venture Wing until I moved completely away from my jacket bc and went to a BP/W for single tanks as well. I have helped people with the bungeed wings, but I didn't like adjusting the bungees. Apparently, once the bungees got adjusted, those divers love their wings as well. It just takes a few more dives to get that adjustment made.

I also use the HP 120s with H valves for single tank dives. It sounds like you are comfortable with less lift than I, or Dive Rite's figures are closer to true. I have a Dive Rite Rec Wing and my son and I have both used it for single tank dives without problems, but have gravitated to the OMS wings for doubles. Neither one of us had any problems with getting the bungies adjusted, but I could see how that could be a problem if you had them uneven, or otherwise maladjusted on the first pass.

I guess this tends to reaffirm my opinion that you really need to try a wing to see if it meets your personal requirements.

[PerroneFord]

Geek,

What brand of wing(s) were you using that didn't seem to offer the rated lift? I've done some dives with LP95 doubles with my 45# DSS wing and felt it offered more lift than needed and I was diving wet.

I also dive a DR Classic wing with steels and it feels like it could lift a house. When I am diving it wet with 95s, at 70ft the thing is barely a third full. And I don't dive HP tanks, just low pressure which are heavier and more negative at similar cuft ratings.

But again, I've watched people in LP121s pumped with cave fills, a few scooters, and several stages/deco bottles and argon, move along just fine with wings rated at 55#. And those wings were nowhere near full. This was in fresh water so in salt, the wing would have had slightly less gas in it.

I've also done wet, saltwater dives with a LP90 and my 27# Pioneer wing and found I needed less than half the wing's capacity. I am using that configuration on Friday for an offshore dive in fact.

In terms of trying wings, I agree. However, I've tried Halcyons (Pioneers and Evolve), Oxycheq, Dive Rite, DSS (torus 45), and Golem Gear, and they all seem to offer lift as stated.

[Geek]

Geek,

What brand of wing(s) were you using that didn't seem to offer the rated lift? I've done some dives with LP95 doubles with my 45# DSS wing and felt it offered more lift than needed and I was diving wet.

I also dive a DR Classic wing with steels and it feels like it could lift a house. When I am diving it wet with 95s, at 70ft the thing is barely a third full. And I don't dive HP tanks, just low pressure which are heavier and more negative at similar cuft ratings.

But again, I've watched people in LP121s pumped with cave fills, a few scooters, and several stages/deco bottles and argon, move along just fine with wings rated at 55#. And those wings were nowhere near full. This was in fresh water so in salt, the wing would have had slightly less gas in it.

I've also done wet, saltwater dives with a LP90 and my 27# Pioneer wing and found I needed less than half the wing's capacity. I am using that configuration on Friday for an offshore dive in fact.

In terms of trying wings, I agree. However, I've tried Halcyons (Pioneers and Evolve), Oxycheq, Dive Rite, DSS (torus 45), and Golem Gear, and they all seem to offer lift as stated.

Dive Rite and Oxycheq I own, but I have not felt it was the brand. I have just gotten the impression that the rated numbers are sort of like horsepower numbers in a 60s muscle car, i.e. you could take anyone's number, divide by two, and have a pretty good estimate. By the way, I like the way the Oxychq wing feels in terms of trim and have been vary satisfied with the small travel type wings from both of those brands. I just don't find a 50 lb wing moving me upward with any authority when wearing doubles. Will it move me? Absolutely. Will it move me and feel like it has capacity to spare? No.

[PerroneFord]

I just don't find a 50 lb wing moving me upward with any authority when wearing doubles. Will it move me? Absolutely. Will it move me and feel like it has capacity to spare? No.

Ahhhh,

Now I have a better sense of what you mean. Ok.