Bag Shooting

[cool_hardware52]

If you flew kites as a kid then you can get the same effect if you think someone needs to follow you. There's no need to carry 2kg extra weight to get your SMB to stand up.

R..

I'm not suggesting that one needs to hang weight on the spool, your hand is enough. I have however tested a couple of designs to see what the minimum required weight to keep the tube vertical at the surface was. The absolute minimum for the smallest SMB was 4 lbs.

My point was that without significant load on the spool, the SMB will be lying on it's side regardless of how full it is.

Tobin

 

[cool_hardware52]

Tobin, what do you put on that line that's 4+ pounds?

I don't hang anything on the spool. I've tried clipping on a backup light, but it's no where near enough load to keep a tube vertical.


My point was that if you need the SMB to stand up, you need to load the line pretty significantly.



Tobin

 

[PerroneFord]

Alright, I'll keep that in mind. I'll try the "hand on spool" thing next time and see how that goes.

-P

 

[Diver Dennis]

It does not have to be standing up all the time. I just give it a yank once in a while and it will stand up. Gives you something to do on your safety stop. I will be a little negative so I can balance my buoyancy with keeping the SMB upright, keeping a slight pressure on the line. It does not take much to, uh, keep it up.
I also have my name printed on mine because when I solo, they know it's me, especially at sites where there be more boats, and divers.

 

[Cacia]

Who are you trying to impress with that? It needs to not sink so you have a stable decompression platform. nothing more. What it looks like on the surface is completely irrelevant. It's an SMB, not a penis!

okay....I am treading lightly here. Rob, you are teasing right? What if you are in high seas with big swells and the boat is searching for you? We sometimes have to wait some time to be spotted and as my friends will attest, I am often shreiking for them to "get those sausages higher!" once I start to decompensate a bit. My buddies find this quite entertaining. I am serious. Often, we can only spot the boat when we are on top of a swell.

My beautiful, new, shiny, stainless steel spool is heavier than my old plastic one, if anyone cares.

 

[PerroneFord]

As "un-DIR" as it may be, I might test out a bag shoot with a reel and see what kind of results that nets. I suspect that shooting from deep (>150ft) would alleviate this problem as the bag would be quite full by the time it reached the surface, but from 70ft it's hard to get enough gas in it to FULLY inflate it. Maybe I'll try to see if I can get one of those 6' or 10ft bags and see how full I can get it from 70ft.

Thanks everyone.

 

[cool_hardware52]

As "un-DIR" as it may be, I might test out a bag shoot with a reel and see what kind of results that nets. I suspect that shooting from deep (>150ft) would alleviate this problem as the bag would be quite full by the time it reached the surface, but from 70ft it's hard to get enough gas in it to FULLY inflate it. Maybe I'll try to see if I can get one of those 6' or 10ft bags and see how full I can get it from 70ft.

Thanks everyone.

What are you using for a bag?

A 50 lbs. open circuit bag is pretty easy to shoot from 70 ft. You only need to get it about 1/3 full at 70. That happens pretty quick when I purge a S600.

I try to get a little negative and "hold" myself at depth with a max inhale, then as the bag leaves I can exhale to keep the bag from pulling me up. (that's the plan anyway )

I haven't tried a closed bag, maybe it takes longer to get 1/3 full.

Tobin

 

[Cacia]

the inflater style shoots like a rocket.

 

[PerroneFord]

Tobin,

This was a borrowed bag. Essentially my buddies 4.5ft closed bag. You can orally inflate it which I did on the second shoot. Or you can inflate it with the drysuit inflate hose or the BCD inflate hose, which I did for the first shoot.

If you use the power inflator, STAND BACK! That puppy puts gas in the bag in a BIG hurry! If you haven't tried a closed bag, I highly recommend it. At least for the entertainment value.

 

[MXGratefulDiver]

Ok, so I had two opporunities to shoot a bag today from about 50-60ft and have a couple of questions.

Me too ... well, actually I shot the bag on the first dive to demonstrate, and my student shot it on the second dive.

1. Is there some trick to get the bag to stand proud on the surface without attaching a lot of weight to it? I shot a 4' bag today and though it was a decent shoot, and there was a good bit of gas in it, it wouldn't stand tall at the surface.

Yes, you grasp the spool firmly in your hand and pull down ... doesn't take a whole lot of tension to make a 4-foot bag stand up.

2. When filling the bag, do you leave some slack line off the spool to give yourself time to let go as the bag takes off? Seems this would be a good idea, but just wondering about the "DIR" way.

No ... the way I do it, you hold the spool and bag in your left hand ... spool between thumb and forefinger, bag between the two middle fingers. There's no need for slack, as the bag and spool are right next to each other. Use your right hand to remove your reg ... blow a tiny puff of air in the bag to make it vertical ... once you're sure nothing's entangled, blow the rest of your lungful of air into the bag. No need to rush the release ... you simply transferred air from your lungs to the bag, so there's no change in buoyancy. Let the bag go as you're replacing your reg ... and before inhaling.

3. If you are using a closed bag and use your BC inflator like I did on my first shoot today, is there any secret to the thing not taking your ARM with it as it goes!? That thing SHOT up with major quickness...

Yeah ... don't overdo the amount of gas you put in the bag. Remember, if you're at 60 feet and only fill it a third full, it'll be essentially completely full when it hits the surface.

Thanks. (And yes I've seen the videos of Andy G. I'm not that good)

When you've done it as many times as AG has, you will be ...

... Bob (Grateful Diver)