Lift bag question....

[dumpsterDiver]

Oh, for pete's sake.

If someone has the skillz to dive safely in those waters, and to that depth, then I'm not seeing the need to make this sound like something you need a specialty class for.

Lifting a small motor with the appropriate tool (a lift bag) is not a big deal. Sheesh. Attach to motor, add air slowly until it almost lifts off the bottom, swim with bag. Vent air every 5-10 feet of ascent.

Yawn.

There's lots of stuff we do, just to do them and gain the experience. This sounds like one of those things, and more benign than most.


All the best, James

I often feel the same way that you do about some of the overly-conservative advice on this site. HOWEVER, I myself got tangled in a lift bag going up from just 60 feet after I had done over 1000 dives. (An octo got loose somehow and got snagged and I got a free ride dragged by my octo).

Years later, I thought I knew what I was doing and almost got myself killed on a solo recovery dive in 180 feet (for a stupid flooded dive scooter).

Take it from someone who is experienced in screwing up, there are many ways to have an accident with lift bags and the consequeces can be significant in 100 ft.

Put simply, you are wrong to trivialize the dive to an open water diver with less than 50 dives.

 

[TBURKE]

If this is a learning experience than try all the methods. Bring it to the anchor line and loop a rope around the anchor line. Connect the lift bag to the motor, inflate it and send it up the anchor line.
You can only do this if no one is on the anchor line.
When the bag starts to rise, move away from the anchor. Open bottom lift bags have a nasty habit of floping over when they reach the surface and dumping their air. Then they come crashing back down to the bottom.
Use an inflator of some sort, not your safe second regulator. the strap on the bottom of the bag has been known to close around your wrist and second stage and drag you to the surface.
It goes without saying DO NOT USE YOUR PRIMARY REG TO INFLATE THE BAG!!!!!!!
One final word. Salvage is work. It is amazing how fast your air disappears when you are working and filling the bag.

 

[fireflock]

How do you plan to find the motor? I would consider that to be the tricky part if the job.

 

[fdog]

My assessment was made by considering the OP's discussion of the dive and his profile.

50 dives in cold water, lowish vis, and feels competent to plan and execute a dive to 100' in these conditions? Some skillz there. Certainly quite a bit more than a typical 50-dive resort diver. A small motor, easily rigged for lift, that wouldn't use more than 1/2 of a small lift bag? Not a difficult task. And, with a buddy with 200+ dives in the same conditions, with salvage experience, as a mentor.....

In that light, this isn't a recipe for disaster. Easy (like doing it with your eyes closed), no. A moderate challenge, yes, and just the type of task that builds a better diver.


All the best, James

 

[Tim GGD]

search & recovery class will explain every thing you need too know about lifting anything small off the bottom.

give that a try before you try anything else!

 

[dumpsterDiver]

My assessment was made by considering the OP's discussion of the dive and his profile.

50 dives in cold water, lowish vis, and feels competent to plan and execute a dive to 100' in these conditions? Some skillz there. Certainly quite a bit more than a typical 50-dive resort diver. A small motor, easily rigged for lift, that wouldn't use more than 1/2 of a small lift bag? Not a difficult task. And, with a buddy with 200+ dives in the same conditions, with salvage experience, as a mentor.....

In that light, this isn't a recipe for disaster. Easy (like doing it with your eyes closed), no. A moderate challenge, yes, and just the type of task that builds a better diver.


All the best, James

Not that I want to really argue with you, but when you have a heavy object in the soft mud, there can be considerable "suction". To over come this, the diver might be tempted to man handle it a little. That might turn visibility to zero (sorta like doing it with your eyes closed)..

Alternatively, the diver could rig a lift bag and very carefully fill it until it just starts to lift out of the mud. However, that may not occur, because the quantity of lift required to break the object free might considerably exceed it's "weight" under water and then you immediately have an object poping out of the mud, destroying visibility and then taking off for the surface because the bag was over filled initially.

It is very easy to get a second stage or something else caught in the object when it unexpectedly "takes off" like a bat out of hell in zero visibility.

Those are a few of the potential problems that immediately come to mind. Some of this stuff, I've learned on my own the hard way. 50 or 500 dives don't mean much when you have zero training or experience in a particular UW activity.

My advice is to play around in shallower water if you want to teach yourself this stuff.

 

[scubafritz]

I would suggest doing the training or specialty course, then you will have the answers to all of your questions.
The tough part is to control the assent of the lift bag and yourself separately.
On top of all that you have to make your safety stop.
On of my dive buddies tied his lift bag 15 ft below an anchor, it was hard to control the lift because a line is needed to activate the release valve on the top of the bag.
Learn it, do it!