Mixing DIN and Yoke Regs on Doubles

[PfcAJ]

Ditching your rig is a great way to get dead.

 

[Vegan Shark]

Even if I can swim the rig up, though, I'll be negatively buoyant when I reach the surface. If "balanced rig" means a rig you'll be neutral with on the surface without the use of extra lift how can someone accomplish that with heavy steel tanks?

From the redundant buoyancy in tropical diving thread it seems like a fair share of people do just use lift bags in case of emergency. Which lift bag do you guys recommend? I saw that the Hollis backpad has a place to put the lift bags too, but I don't understand how you're supposed to reach and grab it when it's at your back.

I am a little unclear on wing failures. It sounds like most incidents are the dump valve or hose coming off....how likely is this really to occur, if you take good care of your gear and inspect it before the dive? These parts coming off spontaneously mid-dive sounds like an insane manufacturing problem, so is it just that some divers pull very aggressively when deflating?

 

[kydaka]

This is something you should seriously consider. Once you start down the tec road you will see that $75 is absolutely nothing. Do you have your bp and harness as well as your 'doubles' wings? Weight harness? Multiple gas computer?..... It's a lot of fun.... but it ain't cheap

If you are concerned about $75, you may wish to consider if tech diving is really for you.......[/QUOTE]

 

[DevonDiver]

Even if I can swim the rig up, though, I'll be negatively buoyant when I reach the surface. If "balanced rig" means a rig you'll be neutral with on the surface without the use of extra lift how can someone accomplish that with heavy steel tanks?

I suggest the background reading first. Then, if you have questions, ask... There's a wealth of information just at your fingertips - on Scubaboard and via Google Search.

From the redundant buoyancy in tropical diving thread it seems like a fair share of people do just use lift bags in case of emergency.

I haven't ever collected the statistics, but I doubt it...

I don't understand how you're supposed to reach and grab it when it's at your back.

It's as easy as touching the small of your back.

I am a little unclear on wing failures. It sounds like most incidents are the dump valve or hose coming off....how likely is this really to occur, if you take good care of your gear and inspect it before the dive?

In technical/cave diving a failure can kill you quite easily. The aim is to eliminate, or mitigate, for all foreseeable failures and contingencies. There is a vast mindset re-calibration needed when moving from recreational diving.

Likelihood (statistical % risk) has a different emphasis when the outcome could be death or serious injury.

In recreational diving, you'll probably get away with as many failures as you'd ever encounter. In technical diving, you probably wouldn't get away with a single one; unless the failure has been effectively planned and prepared for.

These parts coming off spontaneously mid-dive sounds like an insane manufacturing problem, so is it just that some divers pull very aggressively when deflating?

Unlikely to be 'aggressive' dumping. Stuff breaks sometimes... it's Murphy's Law. It's better when you don't let Murphy kill you.

This is something you should seriously consider. Once you start down the tec road you will see that $75 is absolutely nothing. If you are concerned about $75, you may wish to consider if tech diving is really for you.......

To put things in perspective, I pay more than double that, just for a TMx fill on one dive...

 

[waterpirate]

As Devon stated on page 3, there is a form and function to everything, for a reason. 1 of the most entertaining dives I ever did was down in fla. I lurked around while a tech instructor took a new punter into 60fsw with their net bought and assembled doubles rig. He then promptly got tangled, caught, confused ect. Once back on the boat, stuff started coming off, moved, thrown overboard.

Having it assymbled correctly first saves alot of time and agravation.
Eric

 

[Mr.X]

1 of the most entertaining dives I ever did was down in fla. I lurked around while a tech instructor took a new punter into 60fsw with their net bought and assembled doubles rig. He then promptly got tangled, caught, confused ect. Once back on the boat, stuff started coming off, moved, thrown overboard.

Eric

This is called polluting water.

At the same time his instructor should have been giving him some bits of advice?

 

[DevonDiver]

his instructor should have been giving him some bits of advice?

Nothing gets the message across like abject failure!

Some students show up for training without much prior consultation. They can be adamant to dive with it, even when the drawbacks and potential problems are explained. For me, when teaching, I am happy to accept kit within broad(ish) parameters, providing it doesn't hazard safety. I will, however, explain my opinions. I strike a deal... if the kit (I don't recommend) does cause a problem on dives, then it gets replaced and it's done my way. I tend to get my way

 

[Vegan Shark]

Looking at the TDI requirements for the intro tech classes "Decompression Procedures" and "Extended Range Diver" they list use of a lift bag for redundant buoyancy as a required in-water skills.

From Deco Procedures:

5. Demonstrate ability to deploy a lift bag solo and as member of team

6. Demonstrate controlled / staged ascent on lift

bag / emergency ascent line (lost ascent line)

Extended Range Diver:

5. Demonstrate lift bag deployment from depth

and use of bag as back-up buoyancy device
14. On two (2) dives, demonstrate an ascent with

ascent reel and lift bag and perform staged

decompression.

In the equipment configurations section as well it has lift bag required for redundant buoyancy rather than a dry suit. This manual is from 2006, so has TDI since changed their requirements? ,

 

[Jim Lapenta]

Nope still in there. But in reality I do these in my TDI Intro to Tech classes. They are not hard to do once briefed and demonstrated properly. You really should be practiced and proficient at deploying an SMB/Lift Bag from depth before you even start tech training. Using them as a back up ascent line and back up buoyancy are really recreational skills. I teach them in AOW as well.

 

[Vegan Shark]

So you just attach the lift bag to a reel, shoot it up, and use it as a makeshift line? I'll start practicing this in shallow water.

For TDI then, they don't require either a drysuit or double wing as your redundant buoyancy like PADI does, and wetsuit users are fine with just the lift bag? Interesting how agencies come up with different standards for redundancy.