renting isolated doubles

[partridge]

Hi. I am interested in the idea of isolated doubles and researching about them. I have seen the products for isolated doubles where you have to have a special valve for the tank. My question is: Is there a product out there that makes rented tanks with regular valves into isolated doubles?

I have seen a diver here connect the two tanks together and connect his 1st stage to the center of the connector. This gave him two tanks of air but he could not isolate.

Would appreciate any comments regarding the setup itself.

Thanks

oops maybe this should go in the tanks forum. sorry

 

[teknitroxdiver]

Yes, there are soft bands that will cinch down on the two tanks and hold them in the correct position. Also, you can use regular tank bands and just leave them connected until you leave your vacation site. The bands would probably be lighter to travel with, and would lock the tanks in better.

As for a crossover valve to convert independents, they are available, but most are monsterous creations that would cause more problems than they solve, with many more o-rings and yoke valve connections.

Another option, if you were doing a lot of tech diving on the vacation, would be to carry a manifold and bands with you, rent two tanks when you got there, change the valves out and use those tanks for the trip, then un-manifold them at the end of the trip. Be sure and get permission for this though!

 

[wedivebc]

Hi. I am interested in the idea of isolated doubles and researching about them. I have seen the products for isolated doubles where you have to have a special valve for the tank. My question is: Is there a product out there that makes rented tanks with regular valves into isolated doubles?

I have seen a diver here connect the two tanks together and connect his 1st stage to the center of the connector. This gave him two tanks of air but he could not isolate.

Would appreciate any comments regarding the setup itself.

Thanks

oops maybe this should go in the tanks forum. sorry

Why not just dive them independant?

 

[ClassAction]

I'm not really to sure about the benefits of isolated doubles. Many will tell you to sling an 80 (but that doesn't sound fun to me). How bout just bringing a pony?

If you're going to go with the doubles, try the quick draw bracket. They make one for doubles that looks pretty cool.

 

[partridge]

Yeah never even considered independent. I'll take a look at it. Only drawback is you need two 1st stages right? and two SPG's.

Thanks

 

[pt40fathoms]

Yeah never even considered independent. I'll take a look at it. Only drawback is you need two 1st stages right? and two SPG's.

Thanks

If you are diving isolated doubles, you will need two first stages as well! How do you expect to get air if you have to close the isolation valve with only one first stage?

Independent twins are a possibility, however you must practice and get proficient with maintaining balance when it comes to air consumption. You should not breath one down to 500psi then switch to the second. This will cause you to fight with your unbalanced twin tanks in an attempt to maintain your trim. Task loading will increase during the dive with independent twins, but with enough dives (over 100 in my consideration) you can lessen this factor.

I see independent twins as a viable answer to traveling to some countries, where renting twins may not be feasible.

 

[partridge]

As you can see, I am not very knowledgeable in this subject as it is not widely used here or anywhere in the Philippines, I think. Thanks for not jumping on me too much.

So my choices are: isolated doubles, independent doubles or pony bottle. Is this about right? I will research the first two as I already have the last one.

 

[DA Aquamaster]

I normally dive independent doubles and proper gas management requires two reg switches during the dive. You breathe one tank down 1/3 then switch to the other to breathe it down 2/3rds before returning to the first tank to breathe the 2nd third from it. This leaves 1/3 in each tank and with proper planning ensures you have adequate gas in either tank to finish the dive if you have a reg, o-ring or burst disc failure at any point in the dive. Two SPG's are required which adds an extra hose but with only 2 reg switches, the additional task loading is very minimal.

It has the advantage of working very well for travel. I recently returned from a trip where we flew via small private plane precluding to a destination that did not rent doubles. Renting generic 80's and putting them in a set of travel bands worked very well and no change in configuration was required.

 

[wedivebc]

I normally dive independent doubles and proper gas management requires two reg switches during the dive. You breathe one tank down 1/3 then switch to the other to breathe it down 2/3rds before returning to the first tank to breathe the 2nd third from it. This leaves 1/3 in each tank and with proper planning ensures you have adequate gas in either tank to finish the dive if you have a reg, o-ring or burst disc failure at any point in the dive. Two SPG's are required which adds an extra hose but with only 2 reg switches, the additional task loading is very minimal.

It has the advantage of working very well for travel. I recently returned from a trip where we flew via small private plane precluding to a destination that did not rent doubles. Renting generic 80's and putting them in a set of travel bands worked very well and no change in configuration was required.

This is exactly the method I use. the bouyancy difference between tanks is barely noticable, (al lot less than slinging a couple of deco cylinders) and as for task loading, monitoring 2 spgs is not really a huge thing and we all learned to remove and replace a reg underwater when we took open water training so it's really not that hard. I dive this way even with a manifold. Just be sure to practuce on shallow dives before you do anything too challenging.