Doubles? how soon?

[amascuba]

Why can't you get them filled while you wait? I do it all the time. I had a local diver tell me that my dive count would begin to slow down once I moved to doubles. I asked why that was. He said, because your dives will go from 40 minutes each to 2 hours each! He was right!

Allot of shops don't take the time to fill tanks correctly. They do hot fills to fast, which ends up with a fill that is short. I believe that is what TSandM is referring to.

 

[cool_hardware52]

Everybody needs a vermicelli experience with a spool!

The extra gas you have with doubles is really seductive . . . But if you use more than half, then you hauled a lot of tank around to get one dive. If you are going to get TWO dives out of them, you need to be diving a big enough set of doubles, which means you have to carry that weight around. And you can't get a set of doubles filled very well while you wait, either, so you end up needing two in order to have a full tank available all the time, which is more money . . . Sigh.

If you have a extra HP single tank take it with you and transfill between dives.

Example: 2250 psi 72's. Get out of the water with 1000 psi remaining.

Transfill from a HP 130. The tanks will equalize at about 1900.

Transfill from a HP 100. The tanks will equalize just under 1800.

Transfill from an AL80. The tanks will equalize just under 1600.

Of course now you need another tank, and a transfill whip, and an extra fill.....

Simple transfill whips are pretty cheap, it's just a hose and two fittings.

I like LP tanks, transfilling from HP tanks yields useable volumes.

Tobin

 

[PerroneFord]

Man,

I thought Tobin was gonna recommend one of these:

http://www.golemgear.com/p-79-baby-booster-pump.aspx

 

[TSandM]

Intriguing thought, Tobin . . . My husband has HP 100s.

The shop doesn't like to fill doubles that fast, and doesn't feel happy about getting the right mix if they do.

 

[MXGratefulDiver]

Intriguing thought, Tobin . . . My husband has HP 100s.

The shop doesn't like to fill doubles that fast, and doesn't feel happy about getting the right mix if they do.

Hmmm ... I'm hoping they'll make an exception for me on Saturday. After diving tonight, tomorrow, and Friday, I'm gonna need some quick fills for our 3-tanker on Sunday ... (thinking I can get three long dives outta a well-filled set of 119's) ...

... Bob (Grateful Diver)

 

[cool_hardware52]

Man,

I thought Tobin was gonna recommend one of these:

http://www.golemgear.com/p-79-baby-booster-pump.aspx

Perrone,

You need a van full of drive gas bottles, some reading material and a shaving kit, if you want to fill even a small set of doubles with a RB booster.

Those little booster are great if you want to fill a 13 for a RB, but man '0' man are they slow on anything of any size.

Tobin

 

[PerroneFord]

Did you see the fill times in ADM on filling up a set of doubles?? Whoo...

 

[wedivebc]

The extra gas you have with doubles is really seductive . . . But if you use more than half, then you hauled a lot of tank around to get one dive. .

Yes but you amortize your redundant gas over 2 dives so you can actually carry less than using 2 seperate tanks for 2 dives.

 

[cool_hardware52]

Did you see the fill times in ADM on filling up a set of doubles?? Whoo...

No, I missed that article. I have however used that exact booster, during my Blender's Course. The good news all the Trimix fills were into tiny RB bottles.

(You waste less He that way when you screw up )


Tobin

 

[dsteding]

Hmmm ... I'm hoping they'll make an exception for me on Saturday. After diving tonight, tomorrow, and Friday, I'm gonna need some quick fills for our 3-tanker on Sunday ... (thinking I can get three long dives outta a well-filled set of 119's) ...

... Bob (Grateful Diver)

Bob-

If you aren't diving your doubles Thursday/Friday I can take them to the shop Thursday evening for you. I have to run up there anyways to get my tanks filled.