Using AL 80's for Bailout

diverreb · 12th February 2008, 22:23

I was thinking about trying a pair of Aluminum 80's for some dives later this year. I'm an air hog and using 40's or 45's for a 160' - 200' dives are cutting it close for me.

My question is how do you weight yourself, considering the buoyancy of these suckers when empty? If one had to empty both of them on an aborted dive you'd float like a cork if you didn't add a bunch of weight...

If I remember from days of old, there can be five or six pound difference between full and empty.

Do people using these add 10 or 12 pounds of weight just in case they are emptied?

I also just saw some neutrally buoyant Aluminum 80's.... Anyone using them?

Richie

***EBT*** · 12th February 2008, 22:44

Weight as if you have no stages. if you have to empty them, they go up the line.....

***diverklondike*** · 12th February 2008, 22:59

Quote: (Originally Posted by EBT)

Weight as if you have no stages. if you have to empty them, they go up the line.....

Ditto....

mattmexico · 13th February 2008, 04:10

yo

If you can not send them up th eline but are in a cave or do drifting deco you may want to attach a 2 or 3 pound weigth to them, depending on fresh or salt water, prefecence would be the bottom part which will be much more positive buoyant as the neck area as the neck has the valve in it. The weight can be atached easy on BCD cam strap or the ss cam band.

greetings
Matt

mattmexico · 13th February 2008, 04:13

Quote: (Originally Posted by diverreb)

I also just saw some neutrally buoyant Aluminum 80's.... Anyone using them?

Richie

yo

I have some neutreal alm tanks and they are quite heavy. I prefer the regular alm tanks. As I keep some reserves with me in my tanks they never gonna be totally empty to begin with. I would weight for empty tanks and then be a bit heavy with full ones, attach some light weight to the bottom end to keep them from floating up.

Matt

diverreb · 13th February 2008, 13:35

Thanks for the all the info....

I'm going to try a few different things in the Quarry or on a shallow dive to see which works out for me.

Matt, I was thinking the same thing, as far as not being near a line or on a drift.... That's the scenario that I was concerned about.

I can't imagine swimming with two 80's as B/O, but guys I've talked with say that in water they aren't as noticeable as you'd think....

Richie

cramerdn · 13th February 2008, 13:41

Quote: (Originally Posted by diverreb)

I can't imagine swimming with two 80's as B/O, but guys I've talked with say that in water they aren't as noticeable as you'd think....

Do it all the time OC. Usually I cam strap a 2-3 lb weight near the bottom of the tank. Makes that tank its self more neutral when its empty and improves the trim of the tank so the bottom is less floaty.

That way you stay weighted correctlly and any added weight for the bottles is on the bottles and ditchable with the bottles.

netmage · 13th February 2008, 13:42

Quote: (Originally Posted by diverreb)

Thanks for the all the info....

I'm going to try a few different things in the Quarry or on a shallow dive to see which works out for me.

Matt, I was thinking the same thing, as far as not being near a line or on a drift.... That's the scenario that I was concerned about.

I can't imagine swimming with two 80's as B/O, but guys I've talked with say that in water they aren't as noticeable as you'd think....

Richie

Did a long dive at Ginnie w/ a single 80, other than the initial enterance and going thru the lips, didn't even know it was there...

mattmexico · 13th February 2008, 14:18

yo

In order to get some more control over your 80's you could use a but late Amadillo style. I think Dive Rite makes one sidemount fabric butt plate you just attach to the bottom of your regular backplate.

That butt plate or butt fabric allows you to mount the tanks lower on your body into sidemount configuration. That drops the tanks below your armpits, protecting your valves, giving you more space in front of your shoulders as well as bringing the tanks in very tight top and bottom. If you then attach a 2 or 3 lbs weigth to the bottom part you are still very streamlined and have less drag even if your bailout tanks ar almost empty.

Matt

Mikel-Deko · 13th February 2008, 14:44

Hi
There is a big diference if you have trimix or nitrox on it.
For example:
AL80 with Tx15/50 200 bar just a little bit negative. 150bar neutral.
AL80 with Tx10/70 200 bar a little positive.
AL80 with Nitrox 50 200 bar, more than 1 kl neg.

Usually i put two kilos (in salt water) in the Tx tank just to take it down in case i need it.

It was a thread where Mark Chasse explain it with some pictures...
http://www.rebreatherworld.com/gener...bailout-2.html

My two cents.

Mikel

12th February 2008, 22:23	#1 (permalink)
diverreb DE/MD/NJ Wreck Diver Current Rebreather/s: Optima Other Rebreather/s: Join Date: Mar 2007 Location: Dover, DE Posts: 512	Using AL 80's for Bailout I was thinking about trying a pair of Aluminum 80's for some dives later this year. I'm an air hog and using 40's or 45's for a 160' - 200' dives are cutting it close for me. My question is how do you weight yourself, considering the buoyancy of these suckers when empty? If one had to empty both of them on an aborted dive you'd float like a cork if you didn't add a bunch of weight... If I remember from days of old, there can be five or six pound difference between full and empty. Do people using these add 10 or 12 pounds of weight just in case they are emptied? I also just saw some neutrally buoyant Aluminum 80's.... Anyone using them? Richie
(Online)

12th February 2008, 22:44	#2 (permalink)
*EBT* Apprentice Luddite Current Rebreather/s: Classic Kiss Other Rebreather/s: Inspiration Classic Join Date: Feb 2005 Location: UK, Brighton Posts: 1,855	Re: Using AL 80's for Bailout Weight as if you have no stages. if you have to empty them, they go up the line..... __________________ Eagles May Soar, but weasels don't get sucked into jet engines! Rebreather World Terms of service Real diving t-shirts for real divers
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12th February 2008, 22:59	#3 (permalink)
*diverklondike* Moderator Current Rebreather/s: Inspiration Classic Other CCR Other Rebreather/s: Inspiration Classic Other CCR Join Date: Oct 2005 Location: Delaware, USA Posts: 1,461	Re: Using AL 80's for Bailout Quote: (Originally Posted by EBT) Weight as if you have no stages. if you have to empty them, they go up the line..... Ditto....
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13th February 2008, 04:10	#4 (permalink)
mattmexico Rebreather World Writer Current Rebreather/s: Megalodon Classic Kiss Optima RB80 / Clone Other Rebreather/s: Inspiration Classic Evolution Prism Topaz Sport Kiss RB80 / Clone Join Date: Aug 2005 Location: Mexico, Q.Roo, Playa del Carmen Posts: 752	Re: Using AL 80's for Bailout yo If you can not send them up th eline but are in a cave or do drifting deco you may want to attach a 2 or 3 pound weigth to them, depending on fresh or salt water, prefecence would be the bottom part which will be much more positive buoyant as the neck area as the neck has the valve in it. The weight can be atached easy on BCD cam strap or the ss cam band. greetings Matt __________________ N 20' 37.617' W 87' 04.693' www.andreaswmatthes.com
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13th February 2008, 04:13	#5 (permalink)
mattmexico Rebreather World Writer Current Rebreather/s: Megalodon Classic Kiss Optima RB80 / Clone Other Rebreather/s: Inspiration Classic Evolution Prism Topaz Sport Kiss RB80 / Clone Join Date: Aug 2005 Location: Mexico, Q.Roo, Playa del Carmen Posts: 752	Re: Using AL 80's for Bailout Quote: (Originally Posted by diverreb) I also just saw some neutrally buoyant Aluminum 80's.... Anyone using them? Richie yo I have some neutreal alm tanks and they are quite heavy. I prefer the regular alm tanks. As I keep some reserves with me in my tanks they never gonna be totally empty to begin with. I would weight for empty tanks and then be a bit heavy with full ones, attach some light weight to the bottom end to keep them from floating up. Matt __________________ N 20' 37.617' W 87' 04.693' www.andreaswmatthes.com
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13th February 2008, 13:35	#6 (permalink)
diverreb DE/MD/NJ Wreck Diver Current Rebreather/s: Optima Other Rebreather/s: Join Date: Mar 2007 Location: Dover, DE Posts: 512	Re: Using AL 80's for Bailout Thanks for the all the info.... I'm going to try a few different things in the Quarry or on a shallow dive to see which works out for me. Matt, I was thinking the same thing, as far as not being near a line or on a drift.... That's the scenario that I was concerned about. I can't imagine swimming with two 80's as B/O, but guys I've talked with say that in water they aren't as noticeable as you'd think.... Richie
(Online)

13th February 2008, 13:41	#7 (permalink)
cramerdn Living The Dream, Baby!! Current Rebreather/s: Evolution Dolphin Other Rebreather/s: Dolphin Join Date: Dec 2006 Location: Townsville QLD Posts: 458	Re: Using AL 80's for Bailout Quote: (Originally Posted by diverreb) I can't imagine swimming with two 80's as B/O, but guys I've talked with say that in water they aren't as noticeable as you'd think.... Do it all the time OC. Usually I cam strap a 2-3 lb weight near the bottom of the tank. Makes that tank its self more neutral when its empty and improves the trim of the tank so the bottom is less floaty. That way you stay weighted correctlly and any added weight for the bottles is on the bottles and ditchable with the bottles. __________________ "Its better to live one day as a tiger than an entire life as a worm." "But who's ever heard of a worm skin rug?"
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13th February 2008, 13:42	#8 (permalink)
netmage Hello Kitty...... Current Rebreather/s: Megalodon Other Rebreather/s: Join Date: Dec 2005 Location: Coconut Creek, FL Posts: 351	Re: Using AL 80's for Bailout Quote: (Originally Posted by diverreb) Thanks for the all the info.... I'm going to try a few different things in the Quarry or on a shallow dive to see which works out for me. Matt, I was thinking the same thing, as far as not being near a line or on a drift.... That's the scenario that I was concerned about. I can't imagine swimming with two 80's as B/O, but guys I've talked with say that in water they aren't as noticeable as you'd think.... Richie Did a long dive at Ginnie w/ a single 80, other than the initial enterance and going thru the lips, didn't even know it was there...
(Offline)

13th February 2008, 14:18	#9 (permalink)
mattmexico Rebreather World Writer Current Rebreather/s: Megalodon Classic Kiss Optima RB80 / Clone Other Rebreather/s: Inspiration Classic Evolution Prism Topaz Sport Kiss RB80 / Clone Join Date: Aug 2005 Location: Mexico, Q.Roo, Playa del Carmen Posts: 752	Re: Using AL 80's for Bailout yo In order to get some more control over your 80's you could use a but late Amadillo style. I think Dive Rite makes one sidemount fabric butt plate you just attach to the bottom of your regular backplate. That butt plate or butt fabric allows you to mount the tanks lower on your body into sidemount configuration. That drops the tanks below your armpits, protecting your valves, giving you more space in front of your shoulders as well as bringing the tanks in very tight top and bottom. If you then attach a 2 or 3 lbs weigth to the bottom part you are still very streamlined and have less drag even if your bailout tanks ar almost empty. Matt __________________ N 20' 37.617' W 87' 04.693' www.andreaswmatthes.com
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13th February 2008, 14:44	#10 (permalink)
Mikel-Deko Custom Title Allowed! Current Rebreather/s: Inspiration Classic Other CCR Other Rebreather/s: Other CCR Join Date: Jul 2005 Location: Basque Country -Sp- Posts: 414	Re: Using AL 80's for Bailout Hi There is a big diference if you have trimix or nitrox on it. For example: AL80 with Tx15/50 200 bar just a little bit negative. 150bar neutral. AL80 with Tx10/70 200 bar a little positive. AL80 with Nitrox 50 200 bar, more than 1 kl neg. Usually i put two kilos (in salt water) in the Tx tank just to take it down in case i need it. It was a thread where Mark Chasse explain it with some pictures... http://www.rebreatherworld.com/gener...bailout-2.html My two cents. Mikel __________________ Mikel-Deko Basque Country www.olatu.net "DIR is the nanny state for divers who cannot think on their own" Ron Micjan
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