Backup Buoyancy?

[SailNaked]

Is a safety sausage an acceptable form of redundant buoyancy when diving doubles wet. would a lift bag be a better option? assume best case 2x Al80 or worst case 2x Steel120s w/Al80 stage(deco). or is a double bladder wing the only way to go? I understand the best option would be to dive dry or have a second bladder, looking for what is reasonably safe enough. (please do not call me an idiot, I already know that, and yes I will die).

I understand there could be lots of variables, lets assume a hard bottom at 130 in relatively warm clear water. (like Florida).

 

[DA Aquamaster]

Let me answer quick before your demise...

In my opinion a lift bag is better. An SMB is long and skinny and moves up and down a lot more in the water if you are attempting to "climb" a line shot with it.

Also, if you have a lift bag with a dump, you can actually use it directly and vent excess gas on the way up in a vertical ascent - but that takes practice and makes no sense if you have a deco obligation.

A dry suit is the preferred approach, but a double bladder wing works as does just stacking two regular wings. Prevention of a problem is preferred with a focus on maintainence, elimination of failure points high in the wing (use a plain elbow rather than a shoulder dump) but in most cases you do want to be sure you have redundant floatation.

Where you are diving also plays a role. For example a lift bag or SMB is not a viable option in a cave environement, and even climbing out of some wrecks could be a very iffy proposition and a lift bag or SMB would also be near useless inside the wreck.

In just plain old non overhead open water, a lift bag or SMB is perhaps a viable option.

 

[Scott L]

Let me answer quick before your demise...

In my opinion a lift bag is better. An SMB is long and skinny and moves up and down a lot more in the water if you are attempting to "climb" a line shot with it.

Also, if you have a lift bag with a dump, you can actually use it directly and vent excess gas on the way up in a vertical ascent - but that takes practice and makes no sense if you have a deco obligation.

A dry suit is the preferred approach, but a double bladder wing works as does just stacking two regular wings. Prevention of a problem is preferred with a focus on maintainence, elimination of failure points high in the wing (use a plain elbow rather than a shoulder dump) but in most cases you do want to be sure you have redundant floatation.

Where you are diving also plays a role. For example a lift bag or SMB is not a viable option in a cave environement, and even climbing out of some wrecks could be a very iffy proposition and a lift bag or SMB would also be near useless inside the wreck.

In just plain old non overhead open water, a lift bag or SMB is perhaps a viable option.

Within the S Florida confines (diving wet) I have asked several tec instructors this question and they offer differing views just as you have. The one senario of deploying a lift bag and reeling oneself upwards gives me nightmares as I was not a Boy Scout and do not trust my knots. Several of the legends of IANTD recomend the additional wing concept which appeals to me although only one wing is on my rig. This is why I love SB. Food for thought...

P.S. Wetsuits made of Rubatex will greatly reduce the negative weighting issue.

 

[rjack321]

I understand there could be lots of variables, lets assume a hard bottom at 130 in relatively warm clear water. (like Florida).

double Al80s with an AL30 or 40 of O2 would be perfect and not require alot of convoluted redundant bladders etc. That weight of gas you could swim up if you had a wing failure. Would be enough for a 30-40min dive, which is pretty reasonable BT.

 

[Diver0001]

Let me answer quick before your demise...

In my opinion a lift bag is better. An SMB is long and skinny and moves up and down a lot more in the water if you are attempting to "climb" a line shot with it..

On the other hand, it's easier to hang on a blob on the surface. Don't forget the ascent is only part of your problem. Once you're on the surface you need to stay there.

In any event, the blob/bag should not be open-ended.

R..

 

[Tortuga68]

The one senario of deploying a lift bag and reeling oneself upwards gives me nightmares as I was not a Boy Scout and do not trust my knots.

P.S. Wetsuits made of Rubatex will greatly reduce the negative weighting issue.

No knots required to deploy a bag/SMB - just a permanent loop in the end of your line

Not sure how the rubatex wetsuit helps? You should be weighted slightly negative whatever suit you're wearing

Also, if you have a lift bag with a dump, you can actually use it directly and vent excess gas on the way up in a vertical ascent

Same applies to an SMB

 

[Scott L]

No knots required to deploy a bag/SMB - just a permanent loop in the end of your line

Not sure how the rubatex wetsuit helps? You should be weighted slightly negative whatever suit you're wearing




Same applies to an SMB

There are nevertheless two knots on any reel. Line breakage is probaly the biggest concern though.

Rubatex does not compress nearly as much as other neoprene especially at depth which translates to not having your weighting factor increase nearly as much after decent. It is outlined in GUE's dress for sucess book and was also mandated by my GUE instructor or dive dry. I am still relatively new to the tec world so take my thoughts with a grain of salt. rjack321 responce sounds spot on to me...

Welcome to Wetwear - Custom Wet Suits of Rubatex Neoprene for Scuba Diving and All Water Activities

 

[jorge.a.mahauad]

Remember that as a general rule you must have redundant life supporting equipment. You should consider that you are puting your life at risk. Is that worth a USD 600 redundant wing?

A saussage can be a backup for your main liftbag or SMB, but please remember you are using these for surface marking, not for buoyancy.

If you have a problem and get entangled or something you will have tu cut your SMB, liftbag, saussage. In high stress and task loading comming from a lost buoyancy drill, and a tight deco schedulle you will loose two pices of equipment, not one. You are also adding unnesessary risk by having to deploy a device in order to control your buoyancy; that is something you are expected to manage without deploying awnything. Think of your dive team....

Do things right man. Technical Diving is an expenssive hobby and a double bladder or drysuit will not make a substantial difference anyway.

 

[DCBC]

I don't know what I can add to what's already been said. I use a double wing and a dry suit in cold water and also carry a sausage and lift bag (on some dives). Redundant buoyancy is a necessity as far as I'm concerned; at least for the diving I do anyway. Good luck with your choice.

 

[rjack321]

For only 130ft of warm water, what do you need the double steel 120s for?? That's like 50mins of bottom time for me in those conditions. If you need that much gas you'll freeze doing the deco without a drysuit.