Lift bags......DIR perspective???

[wunat]

In the DIR perspective, is there anything one should look for in a lift bag? What's the differences, if any, is there between a DIR and non-DIR perspective on lift bags? What would you recommend me to look into (eg. close circuit and etc.)?

Thanks a ton!!!:huh:

 

[DIR-Atlanta]

In the DIR perspective, is there anything one should look for in a lift bag? What's the differences, if any, is there between a DIR and non-DIR perspective on lift bags? What would you recommend me to look into (eg. close circuit and etc.)?

The first thing to consider is what you are going to actually use the lift bag for. SMB? Signal the boat? Actually lifting something? Give us some idea of what your requirements are, and that will help us answer your question better.

 

[Meng_Tze]

The first thing to consider is what you are going to actually use the lift bag for. SMB? Signal the boat? Actually lifting something? Give us some idea of what your requirements are, and that will help us answer your question better.

Ideed the right question...... usually people looking into liftbags actually want to use them as SMB.....

 

[wunat]

What I have in mind is to use it as an alternate bouyancy device and as aSMB while decompression stops. No intention to actually use it to lift things underwater.

Thanks!!!

 

[Tanked Monkey]

I was in a similiar situation as you last year. I think if you're diving dry, then a closed circuit (cc) bag/marker will do. If you're diving wet, then it would be a good idea to go with a semi-closed (scc). I try to stay away from the open circuit (oc) bags, but YMMV.

Personally, I have the Halcyon SCC, and love it as a general purpose marker/backup bouyancy, but it's not good as a marker for ocean diving 'cause it doesn't protrude so much from the water. I got it when I was diving wet, in preparation for Fundies. Now that I'm diving dry, and passed Fundies, I'm gonna buy the "H" 6' CC sausage. Gives TONS of bouyancy, and sticks so far out of the water it can touch the moon.

Best,
Mike

ps. here's an old thread that I started in May 2005 in my quest to find the perfect general purpose lift bag and spool for Fundies and after. I was a total DIR n00b at the time, so go easy on me: http://www.scubaboard.com/showthread.php?t=95953

 

[Atticus]

I use the Halcyon 6' closed SMB for deco and ocean signaling. I love it. Keep in mind that the cc bags can be orally inflated if you don't like the idea of plugging your dry suit inflator into it. Though the latter works best of course.

The real benefit to the 6 footer is when you're a ways away from the boat.

 

[DIR-Atlanta]

For something that you plan to inflate and let loose (like from a deep deco stop), the SCC works much better. I've also had pretty good luck with the small CC sausages deployed from shallower depths. You have to be careful how much air you blow into it (don't want it to burst), but that's not terribly hard to manage - in fact, if it's pre-loaded in the drysuit pocket, then that's usually not an issue at all.

The 3' SCC (pre-loaded, spooled, and deployed from the drysuit pocket) works well enough as a deco platform and SMB, but as a couple of you pointed out, is not that visible when the boat is a ways away. I know several people who actually carry both sizes of sausage on ocean dives - they use the 3' SCC to do their deco, and then use the 6' SCC (deployed from the MC Pack) to signal the boat once they get to the surface.

The advantage of using the smaller SCC for a deco platform is that its rate of ascent is slower (and therefore easier to control when necessary), and its lift is small enough that you can actually pull it back down by hand if you need to.

The main problem with OC bags is that they sometimes have a habit of "toppling over" at the surface, particularly in rough seas. This can cause some of the gas to spill out, possibly allowing the bag to descend. That type of bag is really designed more for controlled lifts, where the divers intend to surface the bag with its payload. For uncontrolled lifts, an SCC bag is usually preferred.

 

[wunat]

Thank you all for the recommendations. I have decinded to settle with Halcyoin 60lb SCC lift bag as I already have a 6 feet close circuit SMB.

Now just wait for my them to arrive along with my doubles setup. Thanks again.

The other questions I would like your recommendation is how do most people inflate their lift bags? Do you set an extra inflator hose for it or just use your regulator?

 

[matt t.]

You need to be able to maintain control of the bag during the inflation of the bag, and then maintain control of the spool as the bag ascends. I inflate my open circuit bag with the "exhalation" of my primary reg. Some people will take the reg out of their mouth (while going to the back up) and inflate a bag with the primary. IMO this invites a freeflow in cold water. A closed circuit bag can be inflated orally or with a l.p. inflator hose. I inflate mine orally. Why unhook a hose if you don't need to? When inflating any bag, you only need enough gas to get it to start ascending. As the bag rises the gas expands, and up she goes. On a side note; a delrin or plastic spool will spin "in-place" until the bag hits the surface, then it will drop. A metal spool will immediately drop if you let go of it, even while the bag is still ascending. Stick with the delrin!

 

[DIR-Atlanta]

I inflate my open circuit bag with the "exhalation" of my primary reg.

Do you keep the reg in your mouth while you do this? I'd be a little nervous about that - would not want my primary second stage to be anywhere close to something that was headed on a one-way trip to the surface.

What precautions do you take to ensure that the reg does not become entangled in the bag?