Shooting a Bag

[Lil' Irish Temper]

I got a new Dive Rite 50 lbs. Lift Bag this weekend and went to a local quarry and tried using it. Never used a lift bag before, and I won't be taking a course until mid summer that deals with deploying a lift bag.

I used it on an old outboard motor and never was deeper then 25 feet, I figured it was better to try it out in a controlled space.

I used the exhaust tee on my reg to inflate the bag, and I know to get out of the way, keep gear and hands clear, but is there a GOOD website to show how to do a proper deployment?

Since I will be taking the course in Aug. or so I don't want to buy a book then have to buy a different book for the course.

 

[Vie]

http://www.fifthd.com/fifthdnew/education/videos/bag.asp?from=education&level=2

 

[jonnythan]

What course are you taking? If lift bag training is part of the course, why are you trying to learn it beforehand..?

 

[Lil' Irish Temper]

http://www.fifthd.com/fifthdnew/education/videos/bag.asp?from=education&level=2

Vie, Thanks

LIT

What course are you taking? If lift bag training is part of the course, why are you trying to learn it beforehand..?

Because I know of a certain item I would like to recover, before someone else gets it

 

[The Kraken]

LIT,
One of the reasons I went to the long hose is to facilitate the deployment of a lift bag. I take my bungied alternate to breathe from and use the long hose primary to initially inflate the lift bag. This method keeps me well away from being underneath the lift bag for any reason.

Initially inflate the lift bag with short bursts of air until the object being lifted is just ever so slightly negatively buoyant. You can test this by slightly lifting on the lift rope.
When it gets to the point that you can lift the object with relative ease, one or two more short bursts of air well get it started upward. Physics takes care of the rest.

The big thing, don't get your fingers tangled in securing lines and don't get beneath the object being lifted.

If your bag has a valve, you can control the ascent just like you do with your B/C.

Yeah, it's fun to inflate and watch something do a Polaris :lol3: , but don't burst your bag!!

 

[Lil' Irish Temper]

What course are you taking?

Sorry Jonnythan, missed that somehow - Wreck Diver 1 & 2

 

[matt_unique]

There are lot's of techniques for doing most anything. I'm no expert by any means but I have tried a few methods.

I prefer to use my BC or wing inflator hose to 'transfer' air rather than add air initially. If you're neutral, add air to your lift bag (which you will need to hold at least for a few seconds before you let it go), you are now positively buoyant. If you add air you will begin to ascend so you have to get rid of the bag quick. You could coordinate an exhale at the same time you add air to the bag but I found the volume of air I need for the bag is more than that of one exhale. If you need a few extra seconds to get your reel set to fly you may also wish to have a breath of air

I transfer the air so my buoyancy does not change. I need both hands to open the end of the bag, transfer some air with my wing inflator, then grab my reel before I let it fly. Once the bag is heading up I add air back into my wing to become neutral (takes just a second) then return that hand to control the spin rate of the reel.

Bag deployment tends to be humbling until you figure out the method that works for you. Good luck with your practice and remember - it's OK to let go of the reel!!! If it becomes snagged it would pull you up in a hurry.

--Matt

 

[Lil' Irish Temper]

Not sure of a web site but.... There are lot's of techniques for doing most anything. I'm no expert by any means but I have tried a few methods.

Website . . . Bad choice of words on my part. I'm just looking at different methods that work for people, so I can try them out, and see what works for me.

 

[DA Aquamaster]

My preferred technique for shooting a deco bag is to hold the edge of the bag between the knuckles of my left fore and middle fingers while the left hand also holds the inflator and dumps air from the wing into the bag. My right hand holds the reel or spool (normally a finger spool for a deco bag) out in front and well clear. Once enough air is in the bag, I release it and hit the inflate button to replace the few pounds of air in the wing.

I like a finger spool for this application as it is easy to keep enough tension on it to prevent a small open ended bag from upending and dumping gas on the way up. It also has almost zero risk of jamming and if it does all you have to do is release it.

For a lift bag lifting an object, I will use the long hose reg to get as much distance as possible between me and the bag. Locally, rigging an object on the bottom for lift means zero or near zero viz by the time you are done, so you need to be very careful that you are clear of the bag and associated rigging when the bag goes up. With large objects you also want to swim away as fast as possible in the event the bag bursts, rigging fails etc, as the object will usually come back down faster than it went up and you do not want to be there when it re-arrives on the bottom.

For very large objects with one or more 500-1500 lb bags. I will use a separate hose and ball valve or manifold and either be on the surface and/or well away from the bag when I fill it.

 

[Lil' Irish Temper]

Thanks for everyone's input, I used the exhaust method. It worked well, and I came back with all my fingers and toes.

We think is a old bank lock-box or some kind of safety deposit box. I don't have any tools living in the city, so when my buddy get home at 5 were going to his home so we can open it with tools.

If I had my way I'd beat it open with a hammer.