Guide to getting your weighting correct for a Rebreather.

***schford*** · 7th July 2005, 09:17

Well actually my theories and a request for some feedback so we can made a guide to go into the article section as it is a question that comes up time and time again for new Rebreather divers...
I have tested this both Sarah and I got 5kg of weight off doing it this way!

The positives or getting yourweighting correct include: Less to lug around, less air expansion which will make bouyancy easier, less dil will be used as you dont need to compensate for that extra weight.

OK onto the guide....

1 - Go to freshwater enviroment where you can float / sink next to a jetty or pool side where you can leave your supply of weights....

2 - If you are weighted for the sea take off 2kg / 4 or 5 pounds and also make sure you have 50 bar in each cylinder. Do not carry any stages.

3 - Enter water next to Jetty / Pool side , collapse your wing and sink...(this bit should be easy).

4 - Take off 1kg / 2 pounds place on Jetty, now make sure your counter lungs are at minimum or a touch below loop volume.

5 - Empty wing and sink.

6 - Repeat steps 4 and 5 until you no longer sink, now empty your counter lungs by a few litres, you should now be able to sink again.

7 - Write this weight down, due to the way the suit compresses / air comes out in first 2 metres this should be a good weight for you and should mean you can hold a stop between 5m and 3m.

8 - Drop down again and confirm you can hold a 5m stop for 1 minute with minimum loop volume if you can not add 1kg / 2pounds back on.

9 -

thats your weight for freshwater. Write it down now. Mine is 0kg btw...

10 - If you are diving in freshwater then remember to alter your weight for the stagee you carry, eg Steel Fabers take off aprox 1kg / 2pounds per stage, or for alu's take nothing off.

11 - Now to get your weight sorted for the sea we need to do some maths. So go get changed grab some paper and a pencil and a calculator if you need one.

12 - OK go weigh your equipment as it is configured to dive, my Meg is just under 30kg rounded up for ease.

13 - Go weight yourself with your drysuit on, let us assume I am 100kg with my dry suit on.

14 - Add up the weight from step 9 (your kit weight) and your weight from step 13 - this tells us roughly how much water you displace as that is the amount of weight you need to sink with 1l = 1kg in fresh water.

So for me that will be 100kg (my weight) + 30kg (meg weight) + 0kg(I dont wear any weight in fresh water) = 130kg (this works just the same with imperial measurments)

15 - Multiply this by 1.03 (this is the amount that salt water is more bouyant than fresh water) so 130kg * 1.03 = 133.9, rounded up to nearest kg is 134kg

16 - Subtract total from step 14 from Step 15 to give you additional weight you need to wear / carry in the Sea. So 134 - 130 = 4kg

17 - Add total from step 9 to step 16, for me this is 0 plus 4 = 4kg. So I need to wear 4kg in the sea.

18 - Then you just need to adjust your weighting dependant on stages / torch carried and you should be away.

So what do you think guys, if you try it let me know how much weight you drop!

Stuart

PeteS · 7th July 2005, 12:12

Quote: (Originally Posted by schford)

10 - If you are diving in freshwater then remember to alter your weight for the stagee you carry, eg Steel Fabers take off aprox 1kg / 2pounds per stage, or for alu's take nothing off.
Stuart

I'm sure it works just fine, but what are you going to do if you hand off one of your stages to a buddy?

Surely you should be able to carry all or non of your ditchable kit without a bouyancy problem - neither sinking or going all floaty.

I think, and I stress "I think", that you should set yourself up for neutral with no stuff hung on you, and then hang the bits on and compensate with gas in the wing. Then if you ditch anything you can stay in control.

Oh well, flame away.......

***Beanie*** · 7th July 2005, 12:20

Quote: (Originally Posted by PeteS)

I'm sure it works just fine, but what are you going to do if you hand off one of your stages to a buddy?

Surely you should be able to carry all or non of your ditchable kit without a bouyancy problem - neither sinking or going all floaty.

I think, and I stress "I think", that you should set yourself up for neutral with no stuff hung on you, and then hang the bits on and compensate with gas in the wing. Then if you ditch anything you can stay in control.

Oh well, flame away.......

I agree

no flaming here

***schford*** · 7th July 2005, 12:29

No flames from me - I think it is down to an individual outlook.

Personally I use 2m hoses on my stages and I am happy that someone can breath off that without needing to be passed off.

If thats the only pick up any one has found I am a happy bunny

Stuart

***Beanie*** · 7th July 2005, 12:36

Quote: (Originally Posted by schford)

No flames from me - I think it is down to an individual outlook.

Personally I use 2m hoses on my stages and I am happy that someone can breath off that without needing to be passed off.

If thats the only pick up any one has found I am a happy bunny

Stuart

yep the rest of it is sound

3kg seems to work as a sea weight for alot of people

decoweenie · 7th July 2005, 13:07

Quote: (Originally Posted by schford)

Personally I use 2m hoses on my stages and I am happy that someone can breath off that without needing to be passed off.

There will be situations that you might need to lose/take off the stage(s), or actually lost the stage(s).

IMHO, it is better to weight with just what you have don'ed "permanently". And make that as close to neutral as possible. Then use close-to-neutral stages (i.e. AL) so they won't affect your buoyancy/trim much.

So during the dive, if/when you have to take the stage(s) for any reason, your buoyancy remains fairly neutral.

Mark Chase · 7th July 2005, 15:22

I use steel faber light weight stages and they are neutrol in the water riged with a reg and first stage with 100bar in them. With less than 50 bar they float.

I was always taught to get corect weighting without stages and all other ditchable equipment but aside from that the my stages definatly dont alow me to take any weight off the rig

ATB

Mark Chase

Philippe GERIN · 7th July 2005, 15:45

Quote: (Originally Posted by schford)

Personally I use 2m hoses on my stages

I'm truely interested to see how you tidy this on your kit. I guess it takes some practice deploying/stowing.
Best
Philippe

***Louby Lou*** · 7th July 2005, 19:15

Quote: (Originally Posted by Beanie)

yep the rest of it is sound

3kg seems to work as a sea weight for alot of people

Right well you know what we are doing then at Wraysbury a week Sunday then...

Weights for me... I've got to get some of this weight off me

edster · 7th July 2005, 21:09

I wish I had 3kg

I think its currently erm... 17. Admittedly I have a neoprene suit, but even so - with my twin tens in the sea 5kg is enough. Its all a bit of a shock to the system - I think I'm coming over all faint.....

Cheers

Ed

7th July 2005, 09:17	#1 (permalink)
*schford* Despotic Overlord Current Rebreather/s: Megalodon Sport Kiss Other Rebreather/s: Join Date: Jan 2005 Location: London, UK Posts: 3,562	Guide to getting your weighting correct for a Rebreather. Well actually my theories and a request for some feedback so we can made a guide to go into the article section as it is a question that comes up time and time again for new Rebreather divers... I have tested this both Sarah and I got 5kg of weight off doing it this way! The positives or getting yourweighting correct include: Less to lug around, less air expansion which will make bouyancy easier, less dil will be used as you dont need to compensate for that extra weight. OK onto the guide.... 1 - Go to freshwater enviroment where you can float / sink next to a jetty or pool side where you can leave your supply of weights.... 2 - If you are weighted for the sea take off 2kg / 4 or 5 pounds and also make sure you have 50 bar in each cylinder. Do not carry any stages. 3 - Enter water next to Jetty / Pool side , collapse your wing and sink...(this bit should be easy). 4 - Take off 1kg / 2 pounds place on Jetty, now make sure your counter lungs are at minimum or a touch below loop volume. 5 - Empty wing and sink. 6 - Repeat steps 4 and 5 until you no longer sink, now empty your counter lungs by a few litres, you should now be able to sink again. 7 - Write this weight down, due to the way the suit compresses / air comes out in first 2 metres this should be a good weight for you and should mean you can hold a stop between 5m and 3m. 8 - Drop down again and confirm you can hold a 5m stop for 1 minute with minimum loop volume if you can not add 1kg / 2pounds back on. 9 - thats your weight for freshwater. Write it down now. Mine is 0kg btw... 10 - If you are diving in freshwater then remember to alter your weight for the stagee you carry, eg Steel Fabers take off aprox 1kg / 2pounds per stage, or for alu's take nothing off. 11 - Now to get your weight sorted for the sea we need to do some maths. So go get changed grab some paper and a pencil and a calculator if you need one. 12 - OK go weigh your equipment as it is configured to dive, my Meg is just under 30kg rounded up for ease. 13 - Go weight yourself with your drysuit on, let us assume I am 100kg with my dry suit on. 14 - Add up the weight from step 9 (your kit weight) and your weight from step 13 - this tells us roughly how much water you displace as that is the amount of weight you need to sink with 1l = 1kg in fresh water. So for me that will be 100kg (my weight) + 30kg (meg weight) + 0kg(I dont wear any weight in fresh water) = 130kg (this works just the same with imperial measurments) 15 - Multiply this by 1.03 (this is the amount that salt water is more bouyant than fresh water) so 130kg * 1.03 = 133.9, rounded up to nearest kg is 134kg 16 - Subtract total from step 14 from Step 15 to give you additional weight you need to wear / carry in the Sea. So 134 - 130 = 4kg 17 - Add total from step 9 to step 16, for me this is 0 plus 4 = 4kg. So I need to wear 4kg in the sea. 18 - Then you just need to adjust your weighting dependant on stages / torch carried and you should be away. So what do you think guys, if you try it let me know how much weight you drop! Stuart
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7th July 2005, 12:12	#2 (permalink)
PeteS Consent Issued! Current Rebreather/s: Inspiration Classic Inspiration Vision Other Rebreather/s: Join Date: Jun 2005 Location: New Zealand Posts: 533	Quote: (Originally Posted by schford) 10 - If you are diving in freshwater then remember to alter your weight for the stagee you carry, eg Steel Fabers take off aprox 1kg / 2pounds per stage, or for alu's take nothing off. Stuart I'm sure it works just fine, but what are you going to do if you hand off one of your stages to a buddy? Surely you should be able to carry all or non of your ditchable kit without a bouyancy problem - neither sinking or going all floaty. I think, and I stress "I think", that you should set yourself up for neutral with no stuff hung on you, and then hang the bits on and compensate with gas in the wing. Then if you ditch anything you can stay in control. Oh well, flame away....... __________________ Pete S. http://www.steggle.co.nz Every silver lining has a cloud
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7th July 2005, 12:20	#3 (permalink)
*Beanie* give a man an inch....... Current Rebreather/s: Inspiration Classic Other Rebreather/s: Inspiration Vision Join Date: Jan 2005 Location: In da house! yeah baby! Posts: 3,174	Quote: (Originally Posted by PeteS) I'm sure it works just fine, but what are you going to do if you hand off one of your stages to a buddy? Surely you should be able to carry all or non of your ditchable kit without a bouyancy problem - neither sinking or going all floaty. I think, and I stress "I think", that you should set yourself up for neutral with no stuff hung on you, and then hang the bits on and compensate with gas in the wing. Then if you ditch anything you can stay in control. Oh well, flame away....... I agree no flaming here __________________ Beanie Gallery Admin & Library Assistant. www.outlawdivers.org.uk www.beandiving.co.uk www.beanengineering.co.uk
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7th July 2005, 12:29	#4 (permalink)
*schford* Despotic Overlord Current Rebreather/s: Megalodon Sport Kiss Other Rebreather/s: Join Date: Jan 2005 Location: London, UK Posts: 3,562	No flames from me - I think it is down to an individual outlook. Personally I use 2m hoses on my stages and I am happy that someone can breath off that without needing to be passed off. If thats the only pick up any one has found I am a happy bunny Stuart
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7th July 2005, 12:36	#5 (permalink)
*Beanie* give a man an inch....... Current Rebreather/s: Inspiration Classic Other Rebreather/s: Inspiration Vision Join Date: Jan 2005 Location: In da house! yeah baby! Posts: 3,174	Quote: (Originally Posted by schford) No flames from me - I think it is down to an individual outlook. Personally I use 2m hoses on my stages and I am happy that someone can breath off that without needing to be passed off. If thats the only pick up any one has found I am a happy bunny Stuart yep the rest of it is sound 3kg seems to work as a sea weight for alot of people __________________ Beanie Gallery Admin & Library Assistant. www.outlawdivers.org.uk www.beandiving.co.uk www.beanengineering.co.uk
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7th July 2005, 13:07	#6 (permalink)
decoweenie Crash Test Dummy Current Rebreather/s: Other CCR Other Rebreather/s: Other CCR Join Date: Feb 2005 Location: Cairo Posts: 5,487	Quote: (Originally Posted by schford) Personally I use 2m hoses on my stages and I am happy that someone can breath off that without needing to be passed off. There will be situations that you might need to lose/take off the stage(s), or actually lost the stage(s). IMHO, it is better to weight with just what you have don'ed "permanently". And make that as close to neutral as possible. Then use close-to-neutral stages (i.e. AL) so they won't affect your buoyancy/trim much. So during the dive, if/when you have to take the stage(s) for any reason, your buoyancy remains fairly neutral.
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7th July 2005, 15:22	#7 (permalink)
Mark Chase I go down for ages Current Rebreather/s: Classic Kiss Other Rebreather/s: Inspiration Classic Join Date: Jan 2005 Location: Kent Posts: 2,700	I use steel faber light weight stages and they are neutrol in the water riged with a reg and first stage with 100bar in them. With less than 50 bar they float. I was always taught to get corect weighting without stages and all other ditchable equipment but aside from that the my stages definatly dont alow me to take any weight off the rig ATB Mark Chase __________________ Is it supposed to make that noise ? I took my unit to the dive shop and demanded they bolt on every thing that would fit. Join my elite diving teem and get a Tshirt "Doing It Chasey"Hammerhead Eccr Advanced Diving System
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7th July 2005, 15:45	#8 (permalink)
Philippe GERIN ccr apprentice Current Rebreather/s: Megalodon Classic Kiss Other Rebreather/s: Join Date: May 2005 Location: Strasbourg, France Posts: 636	Quote: (Originally Posted by schford) Personally I use 2m hoses on my stages I'm truely interested to see how you tidy this on your kit. I guess it takes some practice deploying/stowing. Best Philippe
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7th July 2005, 19:15	#9 (permalink)
*Louby Lou* XLVI WC! Current Rebreather/s: Inspiration Vision Other Rebreather/s: Inspiration Classic Join Date: Feb 2005 Location: Roman Corinium! Posts: 1,019	Quote: (Originally Posted by Beanie) yep the rest of it is sound 3kg seems to work as a sea weight for alot of people Right well you know what we are doing then at Wraysbury a week Sunday then... Weights for me... I've got to get some of this weight off me __________________ Miss Lou x Use of Rebreather World is subject to the Rebreatherworld Terms and Conditions - Please read! Outlaw Divers - Sssh we're diving! You heff vays uff dealink vis zem, oh Miss Rebreather World Admin! - Rob Davie Feb 06
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7th July 2005, 21:09	#10 (permalink)
edster Mr Cheesebox Current Rebreather/s: Inspiration Classic Other Rebreather/s: Join Date: Apr 2005 Location: Avening UK Posts: 149	I wish I had 3kg I think its currently erm... 17. Admittedly I have a neoprene suit, but even so - with my twin tens in the sea 5kg is enough. Its all a bit of a shock to the system - I think I'm coming over all faint..... Cheers Ed __________________
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