pants!:
The only reason for this is that the Mis-nammed AL-80 only had 77.4 to begin with. The missing 2.6 CF at .08LB/CF eqauls the .2 pounds. It's a minor technicality and part of the AL-80 hoax.
Pete
Sudden and uncontrolled acsent.
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The only reason for this is that the Mis-nammed AL-80 only had 77.4 to begin with. The missing 2.6 CF at .08LB/CF eqauls the .2 pounds. It's a minor technicality and part of the AL-80 hoax.
Pete
Blackwood
Contributor
pants!:
Depends on the pressure to which they fill it.
JeffG
Contributor
What part of "Empty to Full" didn't you understand?Blackwood:
Blackwood
Contributor
Green_Manelishi:
AND, the buoyancy of the tank is the same, full or empty. The content of the tank doesn't change its volume (and the density of the water is more-or-less constant).
In H2Andy's defense (sorry it's weak Andy, but all I can come up with at the moment...) if you do a weight check at the beginning of a dive without a tank (I don't know why... just because), then add a steel tank you would most likely be safe at the end of the dive with an empty tank (assuming it ends close to neutral) however if you did the same and started with an Aluminum, then you would end positive... Which is why when doing weight checks with an AL80 you generally get neutral without the tank, then add 4lbs to compensate for the bouyancy of the tank when it's empty... Of course this means nothing if you've got steel 72's that go bouyant like AL80's 
But in the realm of reality, if it displaces 2lbs of water... it displaces 2lbs of water
It's been fun reading all this...
But in the realm of reality, if it displaces 2lbs of water... it displaces 2lbs of water
It's been fun reading all this...
Blackwood
Contributor
JeffG:
All I'm saying is that different tanks have different pressures which they can hold.
JeffG
Contributor
If you do anything like this, that means you have no clue about buoyancy.kidspot:In H2Andy's defense (sorry it's weak Andy, but all I can come up with at the moment...) if you do a weight check at the beginning of a dive without a tank (I don't know why... just because), then add a steel tank you would most likely be safe at the end of the dive with an empty tank (assuming it ends close to neutral) however if you did the same and started with an Aluminum, then you would end positive... Which is why when doing weight checks with an AL80 you generally get neutral without the tank, then add 4lbs to compensate for the bouyancy of the tank when it's empty... Of course this means nothing if you've got steel 72's that go bouyant like AL80's
H2Andy
Contributor
JeffG:
dang, JeffG, you must have a Master Instructor Card on Social Skills :14:
next, i will prove (mathematically) that when a diver wears a low-profile
mask as opposed to a high-profile mask, he (or she) has less cubic feet
of air in the mask AT THE START OF THE DIVE than the one wearing
the high-profile mask... yet... they both end up with the SAME AMOUNT
they started with...
you dont' believe me?
JeffG
Contributor
So, what does that have to do with anything.Blackwood:
Tell me....LP80 full vs a HP80 full...Which has the bigger swing weight?
kidspot:In H2Andy's defense (sorry it's weak Andy, but all I can come up with at the moment...) if you do a weight check at the beginning of a dive without a tank (I don't know why... just because), then add a steel tank you would most likely be safe at the end of the dive with an empty tank (assuming it ends close to neutral) however if you did the same and started with an Aluminum, then you would end positive... Which is why when doing weight checks with an AL80 you generally get neutral without the tank, then add 4lbs to compensate for the bouyancy of the tank when it's empty... Of course this means nothing if you've got steel 72's that go bouyant like AL80's
But in the realm of reality, if it displaces 2lbs of water... it displaces 2lbs of water
It's been fun reading all this...
A beginning of dive check with a claculated air depletion allowance is better than nothing but it tainted by all the traped air in your gear, suit etc. The real answer needs to come at the end then it's all wetted out. Conveniently it's at the end of the dive that the correct rate is most critical.
I've backed into scuba weight guestimates from my skin-diving weights for a given suit and water but it's just an estimate.
Pete
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