Lift Bag V Smb

[Veritably337]

All: just starting my tec 40 training and am trying to decide between a lift bag or a SMB. The PADI Tec Deep Diver recommends a 100lb lift bag marine yellow, but in the supplemental notes/outlines they seem to lean to a DSMB. Which one is it? I can't figure the benefit of a lift bag for an open water deco hang. It would seem to me that a DSMB takes up less space and is more visible on the surface. I appreciate your responses.

 

[rongoodman]

What does your instructor say? I would buy the DSMB first--I like the Halcyon version.

 

[kensuf]

What does your instructor recommend?

I frequently recommend the Dive Rite "hybrid" -- it has 30# of lift, can connect to a power inflator, and packs nice and tight.

Dive Rite { 5 ft | 1.5 m } Surface Marking Tube w/Built-in Sleeve | Dive Gear Express®

 

[PfcAJ]

Lift bag for lifting, surface marker buoy for surface marking.

Neither of them are for hanging on.

 

[Jared0425]

[QUOTE="PfcAJ,Neither of them are for hanging on.[/QUOTE]

Says who and why?

 

[Reku]

My halcyon closed-circuit 6' with the metal flange is just the best thing since sliced bread. Complete with 52lbs of lift - just in case you need to use it as redundant lift.

 

[lucca brassi]

long sausage it is even better Super Big Diver's Alert Marker, 6' | Extreme Exposure

 

[kr2y5]

I think the reason a big lift bag is sometimes required is because it is considered by some as a redundant source of buoyancy. If you already have a redundant source of buoyancy, such as drysuit + wing, a lift bag is not needed. If you dive in a wetsuit in AL80s, then maybe it's reasonable to carry a lift bag, I'm not sure. I wouldn't rely on a lift bag for buoyancy if my wing suddenly fails, but that's probably a topic for a whole another thread, and I might be wrong.

I know instructors, who believe in "2 is 1, and 3 is 2" (and I think it is implied that 3 is 1, not sure). Maybe the idea is to be doubly redundant.

Neither of them are for hanging on.

Says who and why?

If you hang on a bag, you will not be neutrally buoyant, and if the bag is small, you might end up pulling it underwater, and it won't be visible on the surface (so it won't be serving its purpose as a signaling device).

 

[Patoux01]

If you hang on a bag, you will not be neutrally buoyant, and if the bag is small, you might end up pulling it underwater, and it won't be visible on the surface (so it won't be serving its purpose as a signaling device).

The average smb is at least 5 or 6l. If you're easily able to pull that underwater at the deco stop, there's something strange going on with your weighting imnho.

 

[kr2y5]

Sure, if you are diving a balanced rig, perfectly weighted, you have learned to get your SMB fully inflated, you are at your 20 feet stop, and you tanks are almost empty, then it would be pretty hard to become 6 pounds negative at that point, but by the time you get squared and develop all the proper habits, you will not be hanging on your SMB, either. On the other hand, if you are just starting your class, you are not perfectly weighted, your SMB is not fully inflated, and you are deeper than 20 feet, or have plenty of gas left, you may easily pull your SMB down.

I admit to being one of those people, who used to hang on his SMB, and had not developed proper habits for a long while (and I am sure I still have plenty of wrong habits left to be unlearned). Hanging on your SMB is easier at first if you have questionable buoyancy, but that also makes it harder to really learn proper control. There's absolutely no reason to hang on the bag, if you can avoid it. Why not just learn to do it properly from the beginning.