Double bladder vs. Drysuit

[Divesherpa]

Forgot to add another point
If in OW, oral inflation of the backup bladder is an option. You will only be releasing gas as you decrease depth.

Cheers

 

[AquaTec]

I use my right side hose as my reserve, i have it lokated under my arm and attached to a ring on my chest strap.

If I am doing a fast ascent deep dive [100 ft/min to 300 + feet] I will have both of them hooked to that same ring and connected, once i have hit my bottom depth i disconnect the reserve, I have a tank oring around the hose which keeps it in place so that the male and female peices are actualy touching just not connected.

when it is time to hit the breaks the infaltor buttons is right there in the center of my chest

 

[Divesherpa]

Why the rapid descents?
That's haulin' ass.
Do you often need both hooked up at the same time?

 

[AquaTec]

the rapid descent is based on sinking while negatively boyant..no finning to the bottom.

there are two reasons for it, one is to increase bottom time, and the second is I act as a safety diver for freediving competitions, and their time frames require a 75 - 100 feet per minute descent rates

mostly though it is to increase bottom time,

I only hook both up at the same time, when I am hauling ass based on past experiences. then I disco it at the bottom'

the past experience. in short form

I was to meet a diver at 300 feet, he went down earlier to set the tag [this was for a freediving comapetition] once all the safety divers where in place I would descend down video taping all the way to the bottom [this was for the tv special that some may have seen] my plan was to start hitting the breaks when i saw his lights, well he had a light failure and was using a little mask light to keep an eye on his own situation untill i got there with all the lights in the world, anyways I blew right by him as i did not see his little light, [bad plan on my part] anyways the time it took my to move my hand from the video camera to my chest where the inflator hose was and then to inflate it until i stopped descending, i was at 350 feet. so without having to hook anything up i had travel 50 feet. and it was a lot less than 6 seconds before i started inflating more like one second. my reserve was right there too but it would have required hooking up, and i had the video camera in the other hand as well.
i got back up to 300 to find him laughing his ass off.

so after that i started descending with both hooked up, then deisconnecting one

 

[Divesherpa]

Wow,
Ever thought of mounting a camera to the sled?
or is there no sled?

I'm not a big fan of bombing to 350+. I don't mind the first hundred or so, but after that, I feel better going slower. I've only done it a few times to below 300 and don't care to repeat it. I like to Mellow Down Easy if I can.
Ever thought of adding air on the drop? What about suit squeeze with such a rapid descent and a camera? one hand on the camera and one on the inflator?
Sounds like a recipe for a oh **** to me.

If you had it to do over again would you have done it the same way?

Cheers and safe bombing,
Sherp

 

[SDAnderson]

A worthwhile discussion! I have very little experience with double bladders, but I liked it. In my case, it was nice to be in 80F water wet rather than dry and I just don't see the big hazard to switching from drysuit task-loading to double-bladder task loading. Maybe I'm missing something...

Time for a few questions to betray my ignorance:

The various stowing plans all seem to create delay issues, should the bag be needed. Why not route the inflator exactly the opposite of "normal?" Inflator hose over the right shoulder, bungeed to the right chest D-ring. Run the air supply off the opposite post, through a sequence of innertube retainers.

In the above scenario, what about connecting the inflator to the air supply? I agree, a stowed inflator connected to an air supply is a disaster waiting to happen, but if the inflator is already deployed, does the risk of accidental inflation (through user error or equipment failure) outweigh the task loading issues under stress?

Steven

 

[padiscubapro]

USAF Diver once bubbled...
From what I've read, DIR says double bladders are unsafe because if an inflator gets stuck open, then you have to waste time figuring out which one is stuck. They also say it is extra baggage that is not necessary.

Personally I don't dive a drysuit so I think double bladders are a good idea.

I enter the water with both inflators attached.. I feel the most dangerous time of a dive is when you first enter the water.. If you have a problem at the start on the surface it could be a big deal.. (its not easy to quickly dump stages and the like on the surface - especially in waves) If you are in a dry suit (this is paramount if a back roll is necessary - I've made this dumb mistake more than once) you have to purge your drysuit of gas, so there is very little buoyancy here.. If I'm on a dive boat with a nice ladder I'll go as far as going into the water to make sure as much gas as possible is out... (nothing worse the a big air bubble popping out your neck seal in 30ish water.. brrrrrr)
Once I reach my desired depth I disconnect my extra inflator and check that no air is in the bladder..

 

[Divesherpa]

It's cleaner on the front with the extra inflator stowed. If I ever had to use the thing, I would keep it attached, but I use quality bladders and have never had a problem.

Attempting to reduce clutter is the main reason!

 

[AquaTec]

Divesherpa once bubbled...
Wow,
Ever thought of mounting a camera to the sled?
or is there no sled?

I'm not a big fan of bombing to 350+. I don't mind the first hundred or so, but after that, I feel better going slower. I've only done it a few times to below 300 and don't care to repeat it. I like to Mellow Down Easy if I can.
Ever thought of adding air on the drop? What about suit squeeze with such a rapid descent and a camera? one hand on the camera and one on the inflator?
Sounds like a recipe for a oh **** to me.

If you had it to do over again would you have done it the same way?

Cheers and safe bombing,
Sherp

No sled - Constant Balast, and this was a competition where we had about 20 competitors. the idea was two fold 1 - to video them for spectators/tv and 2 - for gudging to monitor to grab of the depth tag and line.

Remember this story was based on a misscalculation, not the norm.

as for descent i general bomb down to about 50 feet shy of my destination and then start slowing up, as i am a big beleiver in not breaking the planned depth.

I will add air to my drysuit on the way down, i don't use a lot per dive, 1000 psi out of a 12 cu/ft tank i have never experienced any problem with performing the tasks required on an ascent ; like gas switch, ear equalisation, dry suit inflation and bladder inflation.

I agree with the quality bladder statement, i to maintain my gear and feel that mine is a quality product. I put a lot of trust in my gear.

 

[AquaTec]

padiscubapro once bubbled...


I enter the water with both inflators attached.. I feel the most dangerous time of a dive is when you first enter the water.. If you have a problem at the start on the surface it could be a big deal.. (its not easy to quickly dump stages and the like on the surface - especially in waves) If you are in a dry suit (this is paramount if a back roll is necessary - I've made this dumb mistake more than once) you have to purge your drysuit of gas, so there is very little buoyancy here.. If I'm on a dive boat with a nice ladder I'll go as far as going into the water to make sure as much gas as possible is out... (nothing worse the a big air bubble popping out your neck seal in 30ish water.. brrrrrr)
Once I reach my desired depth I disconnect my extra inflator and check that no air is in the bladder..

some more of my thoughts. I agree with you as this is one of the most dangerous times of the dive. but the other most dangerous time of the dive is on the descent. in regards to boyance

once you jump off the boat and establish boyance then all is good, now its time to let all that air out and drop...no matter what speed you descend you are putting air into your bladder to stop your descent, if it fails then you will not stop [until you hit thte bottom] so i think this is the other time that there is a potential for a problem.

once you have established boyance on the bottom and then there is a failure you will not loose all the air in your bladder and you will have time to connect the reserve hose.