Using SMB For Backup Flotation

[mempilot]

BTW, in my above post, you never have more gas in your LB than you are lbs negative. For example, if your rig is 15lbs negative at 150 fsw after your wetsuit is crushed, then you will need 15lbs of lifting gas in the bag to stop a descent. As you kick to ascend, the gas will expand, your suit will expand, and you will need to burp out enough gas to keep it in equilibrium. I recommend stopping every 10 feet or so to make sure you are in control.

 

[RJP]

A proper 50lb lift bag will have a stainless steel snap bolt at the bottom of the lifting strap. You clip it to the crotch d-ring, add enough gas to it to stop the descent, then gather your wits.

How do you add air to a lift bag clipped to your crotch?

Imagine this:

You are diving a deep wall off Cayman in a 3mm wetsuit with double AL80's. Your wing fails at the threads between the inflation hose and the bladder making maintaining bouyancy with the wing virtually impossible.

What do you do?

1. Go for a ride and get bent?
2. Cut the line/let go of the reel, and start your descent into the abyss?
3. Did you bring a backup bag and reel to replace the primary in such an event?

A.) Shame on you for diving a rig you can't swim up without redundant buoynacy. Dry suit or 2nd bladder.

B.) Why do so many people have such crappy reels/spools/technique that the reel jamming is a given in all these scenarios? Never seen a spool "jam" before, but I guess it is possible.

C.) No one had yet mentioned having a BUDDY in any of these situations. The buddy would be able to cut your line if you did have a problem shooting a bag, and would also have a spool and a bag of his own if another one needed to be sent up. Worse case the buddy would be able to assist you in getting to the surface.

I love these fantastically hypothetical situations of risk, that assume that low-likelihood failures are 100% certain but at the same time are completely devoid of the availability of realistic solutions or even standard configurations which would obviate the problem in the first place.

Internet diving at its best!

 

[OH-JJ]

How do you add air to a lift bag clipped to your crotch?

Use your long hose

 

[rstofer]

A proper 50lb lift bag will have a stainless steel snap bolt at the bottom of the lifting strap. You clip it to the crotch d-ring, add enough gas to it to stop the descent, then gather your wits. At this point, you will not need to add any more gas to the bag, as Boyle's Law will take care of the rest. You slowly give a few kicks to rise just a few feet in the water column, just as you would if you still had use of your wing; all while keeping the bag close to your chest, anchored at the crotch d-ring, and one hand stabilizing the top of the bag and the other hand on the OPRV at the top of the bag. As you rise a few feet, you burp the OPRV, and repeat with a few kicks.

Is this approach considering an open bottom LB or a closed circuit LB? The reason I ask is that the closed circuit LB requires oral inflation or inflation via the LP inflator hose. Neither approach seemed very workable after the LB is clipped to the D ring. In fact, the LP inflator hose on the DSS BP/W is very short. It barely comes past the shoulder and certainly not as far down as is common for a BCD.

The open bottom LB would be workable if one of the regulator hoses will reach that far. I am not using a 5' hose so that could be problematic. There is also a good chance the bag will dump at the surface.

My current thinking is to use a closed circuit LB and perhaps a small cylinder of air to inflate it. Weight is an issue - I don't want to hump any more than necessary across the beach and into the surf. But first, I'll try the oral inflation. If I can rig the LB so I can both inflate and dump while the bag is attached, this will become the plan.

On ascent, controlling buoyancy is no more difficult than using a BC.

Richard

 

[OH-JJ]

Is this approach considering an open bottom LB or a closed circuit LB? The reason I ask is that the closed circuit LB requires oral inflation or inflation via the LP inflator hose. Neither approach seemed very workable after the LB is clipped to the D ring. In fact, the LP inflator hose on the DSS BP/W is very short. It barely comes past the shoulder and certainly not as far down as is common for a BCD.

The open bottom LB would be workable if one of the regulator hoses will reach that far. I am not using a 5' hose so that could be problematic. There is also a good chance the bag will dump at the surface.

My current thinking is to use a closed circuit LB and perhaps a small cylinder of air to inflate it. Weight is an issue - I don't want to hump any more than necessary across the beach and into the surf. But first, I'll try the oral inflation. If I can rig the LB so I can both inflate and dump while the bag is attached, this will become the plan.

On ascent, controlling buoyancy is no more difficult than using a BC.

Richard

So if you are diving the standard Rec setup with a 40" octo... That will reach.

 

[battles2a5]

How do you add air to a lift bag clipped to your crotch?



A.) Shame on you for diving a rig you can't swim up without redundant buoynacy. Dry suit or 2nd bladder.

B.) Why do so many people have such crappy reels/spools/technique that the reel jamming is a given in all these scenarios? Never seen a spool "jam" before, but I guess it is possible.

C.) No one had yet mentioned having a BUDDY in any of these situations. The buddy would be able to cut your line if you did have a problem shooting a bag, and would also have a spool and a bag of his own if another one needed to be sent up. Worse case the buddy would be able to assist you in getting to the surface.

I love these fantastically hypothetical situations of risk, that assume that low-likelihood failures are 100% certain but at the same time are completely devoid of the availability of realistic solutions or even standard configurations which would obviate the problem in the first place.

Internet diving at its best!

Making a bunch of posts on how your method is superior to all others, then blaming technique, bad buddy skills, and fanstastically hypothetical situations when people start poking holes in your way. Not THAT is internet diving at its best.

Blowing a bag or riding the bag are both OPTIONS that can be used. Neither are preferable to diving a balanced rig wet or diving dry w/ steels but they are valid options. There are obviously benefits and drawbacks to each. I prefer my way because I feel it leaves me more options. You can feel free to use whatever method you choose.

 

[mempilot]

How do you add air to a lift bag clipped to your crotch?

The same as you add air to any LB. A typical good quality LB has a leash about 6 to 8 inches in lentgh. That places the bottom of the bag in front of your chest, and the top of the bag just over your head.

A.) Shame on you for diving a rig you can't swim up without redundant buoynacy. Dry suit or 2nd bladder.

LOL. Please reread all my posts. 1. Wing 2. Drysuit 3. LB I was giving an example to someone elses post, not my own. I always have at least two forms of bouyancy. BTW, in technical diving, which is where my example was directed (double AL80's), it is impossible to have a rig that one can swim up once bouyancy is lost. Hence, the conversation surrounding backup bouyancy in the first place. You are digging.

B.) Why do so many people have such crappy reels/spools/technique that the reel jamming is a given in all these scenarios? Never seen a spool "jam" before, but I guess it is possible.

Just the fact that you mentioned it is possible is reason enough. I have the highest quality reels and spools, and it does happen. Murphey's Law. Deploying a LB at depth is a task loaded event.

C.) No one had yet mentioned having a BUDDY in any of these situations. The buddy would be able to cut your line if you did have a problem shooting a bag, and would also have a spool and a bag of his own if another one needed to be sent up. Worse case the buddy would be able to assist you in getting to the surface.

When you get to the level of needing a lift bag for redundant bouyancy because of equipment needs, you also get to a point of needing to be self reliant. A buddy is a tool, but should not be relied upon.

I love these fantastically hypothetical situations of risk, that assume that low-likelihood failures are 100% certain but at the same time are completely devoid of the availability of realistic solutions or even standard configurations which would obviate the problem in the first place.

I'm questioning at this point how long you have been diving and to what extent you are making dives. A lot of this is taught in technical dive courses. It isn't made up stuff. I've swum up on a bag from 172 fsw. It's not fantastical at all.

 

[mempilot]

Is this approach considering an open bottom LB or a closed circuit LB? The reason I ask is that the closed circuit LB requires oral inflation or inflation via the LP inflator hose. Neither approach seemed very workable after the LB is clipped to the D ring. In fact, the LP inflator hose on the DSS BP/W is very short. It barely comes past the shoulder and certainly not as far down as is common for a BCD.

Either type of bag works. An open bottom bag is filled via either your primary or secondary regulator. The bottom of the bag will be positioned in the chest region after clipped to the crotch d-ring. If you secondary is an octo, then use it to fill an open bottom bag. If your secondary is bungeed around your neck, then breath off of it and use your primary to fill the bag. A closed circuit bag can be fill orally as you stated, but can be filled from a LP inflator hose more easily. Since your BC inflator is not being used for the wing anymore, use it, or use that LP inflator on your deep deco mix that you more than likely have if you are doing this type of dive in the first place. I never orally inflate my CC LB's. I always use a LP inflator, but orally will work as a backup. The tube will be right in your face clipped off as mentioned.

The open bottom LB would be workable if one of the regulator hoses will reach that far. I am not using a 5' hose so that could be problematic. There is also a good chance the bag will dump at the surface.

With the LB leash clipped off on the crotch d-ring, the bottom of the bag will be about 6 to 8 inches above that (right in the chest mouth area), and the top of the bag/OPRV will be controllable by your hands. An open bag will not dump at the surface if you remain upright, because the leash(clipped to your crotch) will keep the bag weighted at the bottom and upright. If you roll on your back, well, then you may dump the bag. I use CC bags to ensure they don't spill.

My current thinking is to use a closed circuit LB and perhaps a small cylinder of air to inflate it. Weight is an issue - I don't want to hump any more than necessary across the beach and into the surf. But first, I'll try the oral inflation. If I can rig the LB so I can both inflate and dump while the bag is attached, this will become the plan.

CC bags work great. You don't need a small cylinder to inflate them. Just use your LP inflator from your BC/wing or offboard deco mix. You are only adding a fairly small amount of gas to overcome 10 to 15 lbs of negative bouyancy. I wouldn't mess with oral inflation on a CC bag (only as a backup).

On ascent, controlling buoyancy is no more difficult than using a BC.

Only in that it is different, so it must be practiced. The first time you do a skill should not be in an emergency.

 

[netmage]

 

[mempilot]

Hello Kitty has entered the room!

I'm back on the 16th. What's the plan? I've two weeks to blow underwater. Scott, Marc, and I are going down to Largo to dive the following weekend and do a sea trial on possible boat. You in?