Why use 50 lb lift bag?

[redacted]

SMBs often have the OPV on the bottom, while the air is going to be in the top of the bag, making it hard to dump if you need to. Lift bags with the OPV on the top would be easier to adjust the buoyancy on the way up if you were using it as a back-up for a failed wing/BCD.

The OMS DSMBs have a handle at the top and an OPV at the bottom. If you just want it to get to the surface, give it a good shot of gas and let it rip. If you want to control the ascent, hold the handle and vent, as required from the OPV. Practice, practice, practice.

 

[lowviz]

I completed my solo class a week ago, and one of the equipment requirements was a bag with 50 pounds of lift. I've always used a smallish SMB, mainly when hanging at 15 feet for a safety stop in Cozumel. I understand that I need to be properly equipped in case of, for instance, losing the upline on a wreck and having to shoot the bag, tie off the line to the wreck, and use the line to ascend. But why does it have to be a 50 pound lift bag and not an SMB of whatever size?

My solo requirement was to deploy a DSMB of any reasonable size (with a taped-over mask from 25'), ascend slowly while reading the knots on the upline, 3 min (guesstimated) hang, and surface. I thought that it might be a good idea to inflate the bag from my bungied back-up secondary reg. It wasn't. I held on too long and headed up too fast. Never broke the surface but failed the drill.

My point: Entirely instructor dependent.

Lick your wounds and try again. Good preparation for the serious crap that real-life serves up cold and unannounced.

 

[Beiji]

Thanks again for the replies. To answer japan-diver's question: I did ask the instructor, but then I forgot and thought I would just ask here. After spd135 replied, I realized that was my instructor's reason, and then I remembered that it was actually someone else who recommended a lift bag instead of an SMB. Sometimes I get so much new information coming in that I forget and get confused.

 

[Beiji]

My solo requirement was to deploy a DSMB of any reasonable size (with a taped-over mask from 25'), ascend slowly while reading the knots on the upline, 3 min (guesstimated) hang, and surface. I thought that it might be a good idea to inflate the bag from my bungied back-up secondary reg. It wasn't. I held on too long and headed up too fast. Never broke the surface but failed the drill.

It sounds like you had a more challenging class than I did. I like high standards and rigorous instruction but you don't find those qualities in all classes.

 

[lowviz]

It sounds like you had a more challenging class than I did. I like high standards and rigorous instruction but you don't find those qualities in all classes.

No you don't find those qualities in all classes. Very important point. However, once you learn how to find classes that suit your requirements, you are using your dive dollars to effect change that benefits your own interests...

I would greatly regret spending money for a fast cert when there are instructors out there (for the same price) that will make you a much better diver, pass or fail.

 

[Beiji]

No you don't find those qualities in all classes. Very important point. However, once you learn how to find classes that suit your requirements, you are using your dive dollars to effect change that benefits your own interests...

I would greatly regret spending money for a fast cert when there are instructors out there (for the same price) that will make you a much better diver, pass or fail.

After taking a private day of training with Bob Sherwood last month, all my other classes seem to pale in comparison. From here forward, I will be very careful in choosing my classes.

 

[NAM001]

i am going to stick my neck out here and make a guess.

Solo can be with doubles in lue of a single and a pony. and doubles are recommended to be done with a dry suit and there fore the 50# lift would comp for a failed wing or flooded suit????
no flames please ..... just a guess

 

[James R]

So, if there is an SMB with 50 pounds of lift, would there be any reason to also carry a 50 lb lift bag?

Definitely...here are a couple:
1) If your primary bag fails or spills, you can send up another
2) You can signal surface support (if present) with a 2nd bag or SMB that you have an issue/emergency/need help