Sudden and uncontrolled acsent.

[kidspot]

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.

Pete

Like I said ... it's a weak argument ... gives a guesstimated starting point to work from at best... just looking to add a bit of "positive" levity to the discussion

Of course you gotta get to the end of a dive first to find your answer on this one ... one of many points on which we agree...

Aloha, Tim

 

[JeffG]

just looking to add a bit of "positive" levity to the discussion

groan

 

[CIBDiving]

AND, the buoyancy of the tank is the same, full or empty.

Are you serious??? You really believe that statement!?

 

[francousteau]

Then either one is underweighted or the other is overweighted. Weight is weight. It doesn't matter if it comes in lead or tank material.

Obviously, if a diver needs x amount of weight to dive with a steel tank, and uses that same amount of weight with an aluminum tank, he'll be underweighted.

I think you hit it dead on in your post, Aaron. This was a little confusing :06: thought process that Andy put us through, but in the end your post should've settled it.

 

[JeffG]

dang, JeffG, you must have a Master Instructor Card on Social Skills :14:

Paid good money for it too.

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...

True

yet... they both end up with the SAME AMOUNT
they started with...

True. (or close enough for rock and roll)

But what does that have to do with a pressurized tank, such as a scuba tank, where its contents are consumed during the dive.

 

[ClassAction]

If you do anything like this, that means you have no clue about buoyancy.

I'm guessing that you do a lot of solo diving...

 

[JeffG]

I'm guessing that you do a lot of solo diving...

Good guess

 

[H2Andy]

But what does that have to do with a pressurized tank, such as a scuba tank, where its contents are consumed during the dive.

lol

it's sort of like me saying i'm going to prove that water freezes at 0 degrees Celcius

(in other words, that i'm going to prove the obvious)

all in good fun

tomorrow: H2Andy refutes the theory that the world is flat once and for all

 

[kidspot]

tomorrow: H2Andy refutes the theory that the world is flat once and for all

I'll bet we need to show up early to get the 'good' seats for this one, or can we make advance reservations?

 

[Charlie99]

I understand the improper weighting, but what does the material of the tank have to do with it?

An near empty tank of xx cubic feet will be x amount lighter, whether it is steel or aluminum.

Always a good conversation starter. :10:

Seriously, this aluminum vs. steel thing is a real common misconception, so I just routinely challenge posters that seem to think steel tanks have some magical powers such that they don't have the same CHANGE in buoyancy as do aluminum tanks of the same capacity.

------

1. CHANGE in buoyancy is the same for equivalent capacity tanks of air.

2. Steel tanks tend to be more negatively buoyant than aluminum.

3. Steel tanks tend to be lighter than the equivalent capacity aluminum.

#2 means that you don't have to wear as much lead when using a steel tank. Combine that with the lighter in-air weight of steel tanks, and it means a signficant reduction in weight you have to walk in and out of the surf, or haul back up the boarding ladder of a boat.

OTOH, steel tanks have NO advantage as far as overall buoyancy. (For some people steel tanks help trim, for others aluminum trim better).