SeaQuest Black Diamond

[8buck]

Why al80's you ask...

Because I have five of them and no steels soi will make me set of doubles out of 80's till i can afford some steel

 

[WonderSlug]

Howdy


I have a Black Diamond and I know someone else who has one and dives double 120s on it. He has no problems at all handling the 120s on the BD. So AL80 should be a breeze.

You can get the bands via an AquaLung/Seaquest Dealer that will let you do it. Think it was like $60 to $80 last time I looked at it.

I personally dont dive doubles yet, will eventually just dont have the funds now.

I mostly dive a Halcyon BP and wing now, but if you go doubles on the BD tell me the price on a new set of bands for future reference.

Thanks
-=WonderSlug

 

[divemastertim]

I have a Black Diamond and I dive double steel hp 100s with no problems at all.

 

[SeaJay]

bgbill once bubbled...

1 question though, why bother with double AL 80's?

Well, I'll tell you the answers, but you aren't going to like them. I call that we will *not* argue this, k? I'll simply point out the facts.

Your OMS LP125's are rated to 2500 psi, not 3500.

ONE OMS LP125 weighs 45 pounds... Twins would be 90 pounds on your back, plus gas - 15 each @ 3500psi... Plus manifold... You're talking about 125 pounds - just in tanks alone.

LP125's are neutral when empty, and when full are a whopping 15 pounds each... That's 30 pounds, all focused on your back. I submit to you that this would not be nice to his trim, especially if he's diving wet. It'd be entertaining to watch him swim, that's for sure. Been there, done that.

8buck is talking about using a Black Diamond, which has one bladder in it. Given that he's diving wet, that means that he has no redundant source of bouyancy... So if he had a BC failure, he's screwed. 30 pounds of tanks on his back would pin him to the bottom for sure... Probably upside-down. That is, if there was a bottom at all. Last I looked, 8buck was diving in the ocean, who's deepest point was something like 32,000 feet.

Your OMS wings have redundant bladders in them - so as to safeguard you against a bladder failure. That doesn't help, though, if you have torn both bladders on a wreck or have some other issue which prevents you from being able to use your BC. 8buck has no drysuit to act as a redundant source of buoyancy, and his gear is too heavy to swim up - and he can't ditch it, either.

I propose that a better method would be for him to use tanks that are recommended for wet divers - AL80's - and that if he wants more gas, he takes stages. If he takes all of his tanks, he's got 425 cuft of gas and hasn't paid a thing for tanks (he already has them). He'd also have the option of putting different mixes in each tank for deco - you know, 'mix in back gas, 50% to use at 70'... That sort of stuff. He'd spend a lot less time decoing. Why else would he need that much gas? There's no point in taking 330 cuft of gas on an NDL dive.

Double 80's are easy to manage in the water, relatively light weight topside, and allow him some redundancy for safety.

Okay, that last part is an opinion.

8buck, I'd steer clear of steelies until you're using a dry suit. There are a few steel tanks on the market that you might be able to dive wet safely, but they're generally not nice to trim.

A 60 pound (single with gas) 8" LP125 that you're pressurizing past the manufacturer's recommendations by 40% is definitely not one of the recommended tanks for wet divers.

Call it "kool-aid," y'all... I don't care. Kool-aid or not, I've dived those tanks wet... And it wasn't pretty.

 

[Wreckaddict]

Yes, you can run doubles on a Black Diamond. I have a Black Diamond and have used twin alloy 75's on numerous occasions. Minimal difference in size between 75's and 80's.

I now have a SS backplate and wing however.

Regards
Dave

 

[Manos]

Black Diamond and DOUBLES sounds like a joke.

My 2 cents of advice get a wing and a hardplate.
The diference is enormous.

Manos

 

[8buck]

Manos here is the joke... I have a bp/w thanks for asking...

Oh sorry sticking to the joke thing- The question was can you dive double 80's on a black diamond wich i also have.

the question was not hmmm what gear should i get.

Most people know that only a few bc's are set up for both or should i say has the means for both. And that a bp/w is the way to go for doubles...

But hey thanks for the advice if i did not already have a bp/w it would be taken:mean:

 

[kiwijohn]

I used a BD with twin 75's when I first started deco diving. They were good for about 30-40 dives. However in the end the plastic backplate ripped just above the top bolt.

After thinking about it, the BC was fine underwater but it was topside that done the damage. Carrying the tanks up and down beaches to boats, carrying them onto a rocking boat after a dive and (the final straw) waiting in big seas geared up for the ok to role and check the ancher.

It work for me for a while but I have now moved to a backplate. I dont notice too much difference underwater between the two. However I could never use plastic again after having a twinset fall apart, luckily above water.

John

 

[jerseybones]

ditto kiwijohn, had two black diamonds loved the way they fit but i used them alot with single 120s and both had the plastic backplate break, i fixed them but considering that they arent the cheapest of bc's you shouldnt have to! if you want to dive doubles occasionly, go with a bp/wings set or a trans-pac type set-up

 

[bgbill]

SeaJay once bubbled...


Well, I'll tell you the answers, but you aren't going to like them. I call that we will *not* argue this, k? I'll simply point out the facts.

Your OMS LP125's are rated to 2500 psi, not 3500.

ONE OMS LP125 weighs 45 pounds... Twins would be 90 pounds on your back, plus gas - 15 each @ 3500psi... Plus manifold... You're talking about 125 pounds - just in tanks alone.

LP125's are neutral when empty, and when full are a whopping 15 pounds each... That's 30 pounds, all focused on your back. I submit to you that this would not be nice to his trim, especially if he's diving wet. It'd be entertaining to watch him swim, that's for sure. Been there, done that.

8buck is talking about using a Black Diamond, which has one bladder in it. Given that he's diving wet, that means that he has no redundant source of bouyancy... So if he had a BC failure, he's screwed. 30 pounds of tanks on his back would pin him to the bottom for sure... Probably upside-down. That is, if there was a bottom at all. Last I looked, 8buck was diving in the ocean, who's deepest point was something like 32,000 feet.

Your OMS wings have redundant bladders in them - so as to safeguard you against a bladder failure. That doesn't help, though, if you have torn both bladders on a wreck or have some other issue which prevents you from being able to use your BC. 8buck has no drysuit to act as a redundant source of buoyancy, and his gear is too heavy to swim up - and he can't ditch it, either.

I propose that a better method would be for him to use tanks that are recommended for wet divers - AL80's - and that if he wants more gas, he takes stages. If he takes all of his tanks, he's got 425 cuft of gas and hasn't paid a thing for tanks (he already has them). He'd also have the option of putting different mixes in each tank for deco - you know, 'mix in back gas, 50% to use at 70'... That sort of stuff. He'd spend a lot less time decoing. Why else would he need that much gas? There's no point in taking 330 cuft of gas on an NDL dive.

Double 80's are easy to manage in the water, relatively light weight topside, and allow him some redundancy for safety.

Okay, that last part is an opinion.

8buck, I'd steer clear of steelies until you're using a dry suit. There are a few steel tanks on the market that you might be able to dive wet safely, but they're generally not nice to trim.

A 60 pound (single with gas) 8" LP125 that you're pressurizing past the manufacturer's recommendations by 40% is definitely not one of the recommended tanks for wet divers.

Call it "kool-aid," y'all... I don't care. Kool-aid or not, I've dived those tanks wet... And it wasn't pretty.

SeaJay,

Facts are Facts but some of your "Facts" are incorrect.

I stated that 1 LP 125 filled to 3500 psi would give him 165 cu ft of gas, which is more than al 80's doubled would give him.

I never compared the Double LP 125's to the Double AL 80's.

I am aware that the fill pressure on a OMS LP125 is not 3500 psi, its is 2640 psi, not 2500 psi.

The OMS lp 125 weighs 45 lbs and is -9.5 lbs full and neutral when empty, this is at the rated fill pressure of 2640 psi this includes the valve.

I would have to calculate the weight when it is over pressurized, but I don't think it will be -15 lbs, probably closer to -12.5 lbs to
-13 lbs.

A Luxfer al 80 at 3000 psi holds 77.4 cu ft of gas,the cylinder weighs 31.4 lbs when it is full, it is -1.40 lbs, 1/2 full +1.5 lbs and empty it is +4.4 I am not sure if this includes the valve, it wasn't stated in the specs.

Double al 80's would be 61.8 lbs and -2.8 lbs full and start getting positive before it is half empty and have 144.5 cu ft of gas.

It is my opinion that a single lp 125 filled from 3200-3500 would be a better and more managable setup, than double al 80's. Especially with the BC he is currently using.

The point about a catastrophic wing failure is a valid one, that is why I always carry a closed circuit lift bag and a reel, wether I am diving a single wing or a redundant wing.

I dive double steel cylinders either LP 121's, LP 125's or HP 120's, I dive wet, but I also dive where there is a floor at the depth I am diving which is usuallay 220' or less, and am prepared for a catastrophic wing failure.

I did not see in his post where he is diving, He lives in Brookesville so if he is diving in the Gulf he would have to go pretty far offshore to get to 32,000', we go 80 miles offshore and dive in 220'.

BTW how often do people dive in the part of the ocean that is 32,000 feet deep?
I know wall divers do, but usually there isn't anything in the water column worth looking at, at least in my experience.

One of the main points I was trying to express was that a Black Diamond BC is not really suited for doubles, and that a single OMS LP 125 filled to 3500 psi would give him more gas than double AL 80's,and the Black Diamond BC is not a Bad BC for single tanks.

The other Catastrophic failuire you have to worry about with doubles when attached to a plastic BC harness is what happens if it fails in the water? That would not be fun,The Black Diamond is Plastic, Not even ABS.

I definately would not recommend any one dive with 5 AL 80's with the Black Diamond BC.

No where in his post or my reply did I suggest he take 330 cu ft of gas on a NDL dive, and yes I am aware of using deco gases.

Most people I know that dive doubles use either an AL or SS plate, Some use the Tran Pac. I have used an ABS for singles but prefer SS.


I was just giving my opinion and I believe you may have misunderstood what I was saying.

BTW free advice is worth what you pay for it.