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lottie
10-13-2007, 05:45 PM
Okay, I'm showing my dive naivety here.

What is the difference between the different sized tanks out there? - I'm just talking about the recreational tanks (not nitrox). Also is there a difference between Aluminium and Steel? (apart from the buoyancy aspect)

So for example: if a diver (okay, me) was at a steady 60fsw, not hoovering up my air with the tank filled to 3000psi. Would the different tank sizes make any difference to the length of time that i was under the water?

I just got back from doing a dive and took a smaller tank (normally used by the DMs/Instructors) rather than the normal (think they are AL80s - whatever that means) - so i was only under for 31 minutes instead of my average of 45 mins :(

Thanks

hbh2oguard
10-13-2007, 07:18 PM
The size of the tank is how many cubic feet of air. So an 80cf tank has 80 1ft cubes of air(If that makes sense) The bigger the tank the more air you have, so the longer you can last under water. Steel tanks last A LOT longer than AL, I have one that has a hydro stamp of 1963. Also my AL tanks are at a working pressure of 3000psi, while there are numerous working pressures for steel like (2200,3000,3442,3500) and I'm sure there are more. Probably one of the nicest tanks is a high pressure steel tank.

lottie
10-13-2007, 07:37 PM
Thanks for that.
let me get this straight - even if you have a small and a larger tank - both filled with 3000psi. Am i under the assumption that you will have longer underwater with the larger tank??

yohanson
10-13-2007, 07:41 PM
First off, air and nitrox scuba tanks are the same thing. All air tanks can be filled up to 40% O2 as long as it isn't a partial pressure fill. Anything over that requires that the tank be O2 cleaned. But, they are the same tanks.

The larger the tank, the longer one can dive on it assuming it is filled to the same pressure as the smaller tank. Also, the higher the pressure, the more gas it contains. For example, I have two HP 119 steel tanks and I also have a LP 95. All three tanks are the exact same size but the HPs carry about 20 cubic feet of gas. The fill pressure for the HPs is 3442 PSI and the LP is 2400 (well, it's stamped + so I can fill it 10 percent over...but, have had it filled to 3000). And as far as capacity goes, the material a tank is made out of makes no difference.

HTH

lottie
10-13-2007, 07:46 PM
okay, i understand now...
thanks guys :D

Papa Bear
10-13-2007, 09:51 PM
I have to add my 2 cents! The size as mentioned is not as important as capacity at a given air pressure. HP (High Pressure) tanks have a problem, that is filling them full! When you fill a tank it heats up and the air expands and then when it cools or hits the water it will drop about 10% to 20% of the volume of gas and the proportional pressure. A slow fill works better not heating as much. Now over 3000psi is hard to pump! It is hard on the equipment and uses the most energy and creates the greatest wear on the equipment. Most dive boats can pump 3000psi which then being a hot fill will be 2600 to 2800psi. So if you have a 80qft tank filled to 90% you have 90% of 80qft of air or 72qft of air. The steel tank can take the place of lead on your hip, but the aluminum tank will float when near empty. So if you have a 119qft steel tank rated at 3500psi and you get a fill that cools to 3000psa you have apx 100qft of usable air. The best is a steel 95 to 105qft Low pressure tank. Rated to hold 95qft at 2400psi. Now most boats and shops will fill it hot to 3000psi plus or minus and you have 20% over fill or 95qft will have close to 118qft of air compared to the HP 119qft that only has Apx. 100qft! So to me a LP steel is the way to go! So as you should have covered in your basic class the letters and numbers on the tank do matter. After you have been diving awhile as a woman you will blow the doors off most male divers as far as consumption!

yohanson
10-13-2007, 10:57 PM
. So if you have a 119qft steel tank rated at 3500psi and you get a fill that cools to 3000psa you have apx 100qft of usable air. The best is a steel 95 to 105qft Low pressure tank. Rated to hold 95qft at 2400psi. Now most boats and shops will fill it hot to 3000psi plus or minus and you have 20% over fill or 95qft will have close to 118qft of air compared to the HP 119qft that only has Apx. 100qft! So to me a LP steel is the way to go! So as you should have covered in your basic class the letters and numbers on the tank do matter. After you have been diving awhile as a woman you will blow the doors off most male divers as far as consumption!

I've never had my HP119 cool to 3000 psi. I had 3400 in them when I dove Wazee on New Years Day and they dropped to 3200 when I hit the 37 degree water. The AL80s drop about the same. But, how is a LP95 better than a HP119 when they are the same size and have the same buoyancy characteristics when they are at the same pressure? Also, if you have an LP95 filled to 2650 at a shop and you hit the same water temp, doesn't it also drop about the same amount of psi? One last thing, I've never had a problem with getting 3500 psi fills. If I travel and do a liveaboard, I'm not bringing my tanks anyway.

Papa Bear
10-13-2007, 11:32 PM
On the west coast we have 1/2, 3/4. and day boats where you bring your own tank. And you get hot fills. But boats pump to 3000psi without a problem and they cool to around 2700 to 2800. still 15% over fill! If you own your own compressor you would know how hard it is on them. That is why it takes so long for that last 500psi! You must be getting a slow fill or it is in a cold climate! Live aboards usually have 80qft @ 3000 and they consider a good fill to be 2800psi!

Sarah
10-14-2007, 01:01 AM
So psi's is the force behind the air, cubic feet is the amount of air available to breathe.

I would rather have 100 cubic feet available at 2500 psi's than 80 cubic feet available at 3500 psi's, all other things being equal.

Papa Bear
10-14-2007, 01:20 AM
In cave diving you use 105qft or 120qft steel LP tanks filled to 3800plus psi! with 105qft tanks that gives you about 290qft of air for your dive! The steel allows you to take off hip wight and in fresh water with doubles you don't use a wight belt! So yes all things equal LP is the way to go and even if both tanks were 80qft one HP and one LP at 3000psi one is 20% over and one is 15% under! One is a 95qft tank at the start and the HP is a 72qft tank at the start. You can see that in wreck and cave, buddies have to work out tank dissimilarities because you have to have enough air to get the biggest air hog and yourself out just in case it hit the fan!

Papa Bear
10-14-2007, 01:23 AM
It all goes to show you that size counts, but it is also in how you use it! :D ;) :cool:

acelockco
10-14-2007, 05:12 AM
Thanks for that.
let me get this straight - even if you have a small and a larger tank - both filled with 3000psi. Am i under the assumption that you will have longer underwater with the larger tank??


What dive shop do you use? How many dive shops are there in your area?

hbh2oguard
10-14-2007, 06:38 AM
Thanks for that.
let me get this straight - even if you have a small and a larger tank - both filled with 3000psi. Am i under the assumption that you will have longer underwater with the larger tank??

I thought this would have been taught in OW, or for sure in AOW. Not to be mean but isn't this just common sense:confused:

yohanson
10-14-2007, 01:12 PM
On the west coast we have 1/2, 3/4. and day boats where you bring your own tank. And you get hot fills. But boats pump to 3000psi without a problem and they cool to around 2700 to 2800. still 15% over fill! If you own your own compressor you would know how hard it is on them. That is why it takes so long for that last 500psi! You must be getting a slow fill or it is in a cold climate! Live aboards usually have 80qft @ 3000 and they consider a good fill to be 2800psi!

Or filled in a water tank. I don't have my own compressor but none of the local dive shops seem to have a problem filling my tanks. Getting back to the LP95/HP119, how can the LP95 be preferable to the HP119 when they're bascially the same tank with a different burst disk? The 119 has 95 cu. ft. of gas at 2640, 107 cu. ft. at 3000 and 119 cu. ft at 3442 psi.

yohanson
10-14-2007, 01:14 PM
So psi's is the force behind the air, cubic feet is the amount of air available to breathe.

I would rather have 100 cubic feet available at 2500 psi's than 80 cubic feet available at 3500 psi's, all other things being equal.

And you would have a much larger and heavier tank in that scenario.

lottie
10-14-2007, 02:23 PM
I thought this would have been taught in OW, or for sure in AOW. Not to be mean but isn't this just common sense:confused:

It probably was mentioned in the OW book (will have to have another look to check) - maybe i didn't understand it as much as I do now and didn't take in the information.
And it probably is common sense...but i couldn't remember hence why I asked.

lottie
10-14-2007, 02:26 PM
What dive shop do you use? How many dive shops are there in your area?

How is that relevant?

Most of the dive places here are attached to a resort. There are a couple that are independant (and they cost more), but they are up in the north (about a 90 min drive, to then have the boat come back down south to do the actual diving)

acelockco
10-14-2007, 02:46 PM
Just wondering what shop you use?

I have a friend going to St. Lucia for a vacation shortly.

Like2dive
10-14-2007, 04:14 PM
I'm not an expert on this. My wife & I just switched over to Steel Tanks 2 months ago. I wish I had switched sooner. We had alum 80's. Actual capacity on an alum 80 is 77 CUft. On our steel 80's it is 80 CUft.Pressure rating for our Alum 80 was 3000 psi on our steel 80 it is 3550 psi. So I am carrying 20% more air in a much smaller tank. The steel tank is 9 inches shorter than the equiv. Alum tank. I was able to shed 8 pounds of lead from my belt, I now dive with only 4 lbs instead of 12 lbs and I do not go buoyant and the end of my dive. Pamela has shed all her weights. Lets see... mmmm... lighter smaller package that carries 20% more air and lets me shed up to 10 lbs weight. Since you have to wear a tank anyway - It's a no brainer Steel ROCKS!! We do a lot of deep wreck diving, I find myself surfacing with 1500 - 1600 psi after a deep wreck dive, the extra air increases my safety margin, and the higher capacity in the smaller package has made our diving experience much more satisfying.

hbh2oguard
10-14-2007, 06:07 PM
Lotte as long as you learned and everything is clarified, the post was well worth it!:) :) :)

acelockco
10-14-2007, 08:28 PM
I'm not an expert on this. My wife & I just switched over to Steel Tanks 2 months ago. I wish I had switched sooner. ......... I now dive with only 4 lbs instead of 12 lbs and I do not go buoyant and the end of my dive. Pamela has shed all her weights. .................
and the higher capacity in the smaller package has made our diving experience much more satisfying.


Steel cylinders are great, but aluminum do have their place as well. After using some steel cylinders on vacation, I have to agree with you 100% on how much of a difference they actually do make. The additional air you get really increases your margin of safety as well, giving you enough air to get to your no-deco limit with a nice amount to spare.

The one thing I would warn is about your wife loosing all of her weight. Remember you should have enough ditchable weight that in an emergency situation she could drop it if necessary.

The only reason I still dive aluminum cylinders is because I own 9 of them right now and don't really want/have to spend the money it would take to replace them all.

amtrosie
10-14-2007, 09:13 PM
I have to add my 2 cents! The size as mentioned is not as important as capacity at a given air pressure. HP (High Pressure) tanks have a problem, that is filling them full! When you fill a tank it heats up and the air expands and then when it cools or hits the water it will drop about 10% to 20% of the volume of gas and the proportional pressure. A slow fill works better not heating as much. Now over 3000psi is hard to pump! It is hard on the equipment and uses the most energy and creates the greatest wear on the equipment. Most dive boats can pump 3000psi which then being a hot fill will be 2600 to 2800psi. So if you have a 80qft tank filled to 90% you have 90% of 80qft of air or 72qft of air. The steel tank can take the place of lead on your hip, but the aluminum tank will float when near empty. So if you have a 119qft steel tank rated at 3500psi and you get a fill that cools to 3000psa you have apx 100qft of usable air. The best is a steel 95 to 105qft Low pressure tank. Rated to hold 95qft at 2400psi. Now most boats and shops will fill it hot to 3000psi plus or minus and you have 20% over fill or 95qft will have close to 118qft of air compared to the HP 119qft that only has Apx. 100qft! So to me a LP steel is the way to go! So as you should have covered in your basic class the letters and numbers on the tank do matter. After you have been diving awhile as a woman you will blow the doors off most male divers as far as consumption!


Several things need clarification here.

1. A L.P. tank volume rating is predicated on the volume of gas with 2640 psi. in the cylinder. NOT 2400 psi.!!!!

2. The correct symbol for measured volume is cu.ft. (cubic feet). The "q" symbol is a symbol denoting a heat quotient. The "Q" symbol is utilized in the stock trades group for stock trading.

3. Nitrox denotes a mixture found with in the cylinder and stands for Enriched Air (Oxygen). It can be any mixture that is not 21% (20.9% to be exact-er) and 79% ish Nitrogen. So 32%, 36%, 40%, 23% are ALL Nitrox mixtures. It is the content and make-up of the gas found within the cylinder, it is not a different cylinder. Just greater care is taken in the cleanliness of the cylinder.

4. L.P. stands for Low Pressure, and is any "working pressure" below 3000 psi. That includes tanks rated for a working pressure of 2640 psi., that are stamped 2400 + (the plus is the 10% over fill component). This also includes the "old" steel 72's that are rated for 2150 psi. (if memory serves me).

5. H.P. stands for High Pressure and denotes a tank with a working pressure of more that 3000 psi. Steel 120's have a working pressure of 3500 psi. Steel 119's have a working pressure of 3442 psi.

NOTE: It must be noted here that it is fairly common practice to "over fill" tanks, that is pressurize past the rated tank pressure, I will not comment on that practice, nor advise on the wisdom of that practice

6. Most Aluminium tanks have a rated pressure of 3000 psi. (some 3300 psi). These are neither denoted as high or low pressure cylinders.

ALL SCUBA CYLINDERS ARE HIGH PRESSURE CYLINDERS!! It is just that some are high er pressure than others.

7. Volume of gas in a cylinder is noted as cu. ft. and is the quantity of gas that the cylinder is capable of handling. All other nations rate this in "BAR"s (derived from the Greek "baros", which is a weight measurement)

8. P.S.I. (pounds per square inch) is the "power", or better yet, the number of gas molecules that are crammed into a specific space. So the rush of gas that escapes the valve as it is turned on can be a good indicator of the psi. in a cylinder.

Now as to the comments of why one type of cylinder is better than another (steel vs. aluminum) The basic argument can be boiled down in to the buoyancy characteristics of a cylinder when it reaches it's lowest practical volume. ( this is why weight checks are done with 500 psi in the tank) An Aluminum tank becomes positively buoyant when it reaches critical pressure (500 psi. for the scuba diver). Most Al. 80 tanks will be 4.5 to 5.0 lbs. positive when empty, that is it "pulls" you up when empty, as opposed to "pushing" (weighing) you down when full. (about 8 lbs. negative) So the total "swing" of weight is 12 lbs. which must be accounted for on the weight belt. The benefit if the steel tank is the greatly diminished "weight swing" from full to empty. Most steel tanks will still be slightly negatively buoyant when empty. So the diver does not require as much weight to dive due to the better buoyancy characteristics of the steel tank. The added bonus of this tank is that, in not carrying as much weight on the belt, the diver does not work as hard on the dive carrying the lead on the belt, so has better gas consumption. Which equals longer bottom times.

This may be more information than originally sought, but hopefully it will also answer the questions after the question.

acelockco
10-14-2007, 10:14 PM
amtrosie,

Thanks for posting that, hopefully that gets everyone on track!

Just a quick note, not all aluminum cylinders are positive when empty. A good example of that is the aluminum pony bottles that are always negative (even if it is very little and rarely gets empty anyway...hopefully.)

Papa Bear
10-14-2007, 10:32 PM
First I know it is Cubic just like BTW and other abbreviations I use for the qft. Just shorter and easier. Next the "old 72's" were rated at 2250 not 2150! Next I dive with 105s and 120s that ARE 2400psi! So I not sure where you info comes from and I don't care weather it is right or wrong, but don't correct me about tanks, I use quite a number of them in a lot of different circumstances. If you want to state you opinion then fine! But don't speak for me please or change what I said in anyway. I live and dive in the real world all over it and see a lot of combos and know that some places in the world you are lucky to get 2800psi! And some of those places are right here in the states! I have been on many dive boats in California that advertise 3500psi fills. What they don't tell you is you will be waiting a long time for hot fill. My 2400psi 120 is filled to 2800 with ease and that my friend equals almost 20% over and then I have over 140 CUBIC Feet of air. So my point was not to be too technical, but to suggest the differences in tanks and amount of air each will hold. Some people think that a smaller 119 HP 3500psi tank is going to hold as much as my 120 LP 2400psi steel and my point is now way no how! Not in the real world all theory aside! So please don't quote me in the future when opinions are being given! C U later!

hbh2oguard
10-14-2007, 11:55 PM
And let there be peace:eek:
Papa I have to say that you have convinced me to try to trade the hp100 DIN I have that I can't use, for a lp steel.

rubber chicken
10-15-2007, 02:18 AM
Several things need clarification here....<snip>

7. Volume of gas in a cylinder is noted as cu. ft. and is the quantity of gas that the cylinder is capable of handling. All other nations rate this in "BAR"s (derived from the Greek "baros", which is a weight measurement)

8. P.S.I. (pounds per square inch) is the "power", or better yet, the number of gas molecules that are crammed into a specific space. So the rush of gas that escapes the valve as it is turned on can be a good indicator of the psi. in a cylinder. .....<snip>




Just a small correction on these points.

Most of the rest of the world measure cylinder volume in LITRES, 3, 5.7, 7, 10.5, 12, 15, 18, 20.... whatever.
"BAR" is the SI unit of measurement for pressure, being slightly less than 1 atmosphere. 1 bar = 14.5 psi,
Hence a 12L steel cylinder at 232bar contains 2784 litres of gas, a 10.5L cylinder at 300bar contains 3150 litres etc etc.

HTH.



PS: Come on America, get with the program, Join the Metric system!:D

Tigerbeach
10-15-2007, 03:15 AM
Thanks for that.
let me get this straight - even if you have a small and a larger tank - both filled with 3000psi. Am i under the assumption that you will have longer (time) underwater with the larger tank??

Lottie, there are too many variables at play to really answer your question.

The simple answer is; I think you are asking if all tanks that have a full working pressure of 3000 psi hold the same amount of air, the answer is "no".

In this case the tank with the larger capacity should last the longest time underwater. However, there are many other variables at play.

Such as: Are the two tanks going on the same dive with the same diver?
If a man has a bigger tank than his female buddy, he might suck up more air and finish sooner. What depth are you diving? How hard will you be working? What is the water temperature?
All these can impact the bottom time with a tank of any size.

Papa Bear
10-15-2007, 04:11 AM
Lottie, there are too many variables at play to really answer your question.

The simple answer is; I think you are asking if all tanks that have a full working pressure of 3000 psi hold the same amount of air, the answer is "no".

In this case the tank with the larger capacity should last the longest time underwater. However, there are many other variables at play.

Such as: Are the two tanks going on the same dive with the same diver?
If a man has a bigger tank than his female buddy, he might suck up more air and finish sooner. What depth are you diving? How hard will you be working? What is the water temperature?
All these can impact the bottom time with a tank of any size.

Well said! A single 72 has as much air as a closet. If you close the door and just sit there you will have a long time, but if you jump up and down and run in place, it won't last so long. The best thing I can tell you about air consumption is just dive a lot and become comfortable and you will be bringing extra air back!

hbh2oguard
10-15-2007, 04:17 AM
The best thing I can tell you about air consumption is just dive a lot and become comfortable and you will be bringing extra air back!

Almost true, you'll be lasting longer, or atleast on my part because I'll still suck my tank dry:)

Papa Bear
10-15-2007, 04:55 AM
Almost true, you'll be lasting longer, or atleast on my part because I'll still suck my tank dry:)

Your not a girl!:D Most I dive with even in warm water bring some back!:rolleyes: Most run out of bottom time before air!:cool:

rubber chicken
10-15-2007, 08:18 AM
It's because they can't talk underwater!:D

lottie
10-15-2007, 12:44 PM
Well said! A single 72 has as much air as a closet. If you close the door and just sit there you will have a long time, but if you jump up and down and run in place, it won't last so long. The best thing I can tell you about air consumption is just dive a lot and become comfortable and you will be bringing extra air back!

Hey PapaBear - that's a good analogy...thanks :D

Papa Bear
10-15-2007, 03:24 PM
It's because they can't talk underwater!:D

That's why we don't let them use the AGA masks!:eek: :rolleyes: ;)

Papa Bear
10-15-2007, 03:25 PM
Hey PapaBear - that's a good analogy...thanks :D

Your welcome! Dive safe and dive often! :D :cool:

BamaCaveDiver
10-15-2007, 03:48 PM
I'm not an expert on this. My wife & I just switched over to Steel Tanks 2 months ago. I wish I had switched sooner. We had alum 80's. Actual capacity on an alum 80 is 77 CUft. On our steel 80's it is 80 CUft.Pressure rating for our Alum 80 was 3000 psi on our steel 80 it is 3550 psi. So I am carrying 20% more air in a much smaller tank. The steel tank is 9 inches shorter than the equiv. Alum tank. I was able to shed 8 pounds of lead from my belt, I now dive with only 4 lbs instead of 12 lbs and I do not go buoyant and the end of my dive. Pamela has shed all her weights. Lets see... mmmm... lighter smaller package that carries 20% more air and lets me shed up to 10 lbs weight. Since you have to wear a tank anyway - It's a no brainer Steel ROCKS!! We do a lot of deep wreck diving, I find myself surfacing with 1500 - 1600 psi after a deep wreck dive, the extra air increases my safety margin, and the higher capacity in the smaller package has made our diving experience much more satisfying.

Not quite...you are only carrying slightly less than an additional 4cuft (3.89610 cuft) in the steel 80 versus the AL 80. The fill pressure is just shy of 20% difference; 3550psi is about 18.333% greater than 3000psi. The higher fill rating on the steel cylinder is what allows you to carry an equal amount of gas in a smaller container.

BamaCaveDiver
10-15-2007, 03:54 PM
First I know it is Cubic just like BTW and other abbreviations I use for the qft. Just shorter and easier. Next the "old 72's" were rated at 2250 not 2150! Next I dive with 105s and 120s that ARE 2400psi! So I not sure where you info comes from and I don't care weather it is right or wrong, but don't correct me about tanks, I use quite a number of them in a lot of different circumstances. If you want to state you opinion then fine! But don't speak for me please or change what I said in anyway. I live and dive in the real world all over it and see a lot of combos and know that some places in the world you are lucky to get 2800psi! And some of those places are right here in the states! I have been on many dive boats in California that advertise 3500psi fills. What they don't tell you is you will be waiting a long time for hot fill. My 2400psi 120 is filled to 2800 with ease and that my friend equals almost 20% over and then I have over 140 CUBIC Feet of air. So my point was not to be too technical, but to suggest the differences in tanks and amount of air each will hold. Some people think that a smaller 119 HP 3500psi tank is going to hold as much as my 120 LP 2400psi steel and my point is now way no how! Not in the real world all theory aside! So please don't quote me in the future when opinions are being given! C U later!

Actually PB, a tank is a vessel for containing non-pressurized liquids; a cylinder is the proper vessel for containing gases under pressure (sorry, but after your reply I just couldn't let that one slip by :p )

There are LP and HP 120's out there (the LP version being a heavy mutha!) These behemouths can't be beat for longer dives when they are pumped up to around 4000psi :eek: (if you know of anyone looking to get rid of a couple of those monsters, I would love to add a pair to the collection.)

hbh2oguard
10-15-2007, 03:58 PM
Of course I brings SOME air back, not a lot, but it’s pretty hard to run out of bottom time during lobster season when the majority of my dives are pretty shallow looking for bugs. There is just always the question, of how much some will be:)

amtrosie
10-15-2007, 04:02 PM
First I know it is Cubic just like BTW and other abbreviations I use for the qft. Just shorter and easier. Next the "old 72's" were rated at 2250 not 2150! Next I dive with 105s and 120s that ARE 2400psi! So I not sure where you info comes from and I don't care weather it is right or wrong, but don't correct me about tanks, I use quite a number of them in a lot of different circumstances. If you want to state you opinion then fine! But don't speak for me please or change what I said in anyway. I live and dive in the real world all over it and see a lot of combos and know that some places in the world you are lucky to get 2800psi! And some of those places are right here in the states! I have been on many dive boats in California that advertise 3500psi fills. What they don't tell you is you will be waiting a long time for hot fill. My 2400psi 120 is filled to 2800 with ease and that my friend equals almost 20% over and then I have over 140 CUBIC Feet of air. So my point was not to be too technical, but to suggest the differences in tanks and amount of air each will hold. Some people think that a smaller 119 HP 3500psi tank is going to hold as much as my 120 LP 2400psi steel and my point is now way no how! Not in the real world all theory aside! So please don't quote me in the future when opinions are being given! C U later!




My, oh my, oh my, oh my!!!! :rolleyes:



Your issues with the dive boats in California, land of the vanishing dream, would obviously be your particular issue. That was not, is not, will not, be the subject of the question and answers. What happens there is not what happens every where else! We, here in Florida, while having difficulty counting ballots, have mastered the art of truth telling with regards to tank filling and advertising. Thank you for pointing out that my memory of 72's was off slightly.

Thank-you, Rubber chicken, for correcting me on the metric equivalents of volume and pressure. Proving in the process the superiority of the metric system. :D My bad!


One other thing, the minute we set fingers to keyboard, we invite critique of our statements.......food for thought

acelockco
10-15-2007, 05:34 PM
Well said! A single 72 has as much air as a closet. If you close the door and just sit there you will have a long time, but if you jump up and down and run in place, it won't last so long. The best thing I can tell you about air consumption is just dive a lot and become comfortable and you will be bringing extra air back!


Are all closets 72 cubic feet?

Papa Bear
10-15-2007, 05:57 PM
There are LP and HP 120's out there (the LP version being a heavy mutha!) These behemouths can't be beat for longer dives when they are pumped up to around 4000psi :eek: (if you know of anyone looking to get rid of a couple of those monsters, I would love to add a pair to the collection.)

We call it the water heater! The wight I carry in total doesn't change as you know, just the amount on my belt! But with camera in hand I can use all the extra time I can get to get the shot. For Cave I like 105s! Hard to beat and not quite as big as the "Water Heater"! :D :rolleyes: :cool:

Papa Bear
10-15-2007, 05:59 PM
Are all closets 72 cubic feet?
When I was growing up ya, not so much now! LOL :D :rolleyes: :cool:

Papa Bear
10-15-2007, 06:00 PM
Of course I brings SOME air back, not a lot, but it’s pretty hard to run out of bottom time during lobster season when the majority of my dives are pretty shallow looking for bugs. There is just always the question, of how much some will be:)

All you ever need is enough! ;)

lottie
10-15-2007, 06:20 PM
Are all closets 72 cubic feet?

ROFL :D :D

hbh2oguard
10-15-2007, 06:32 PM
Are all closets 72 cubic feet?

Have you ever seen MTV's cribs some of them have a closet the size of a descent size house.:) So maybe a phone booth would be better to compare to, if they still exist:D I saw somewhere that the phone booth had the same amount of air as an 80.

Papa Bear
10-15-2007, 06:36 PM
Have you ever seen MTV's cribs some of them have a closet the size of a descent size house.:) So maybe a phone booth would be better to compare to, if they still exist:D I saw somewhere that the phone booth had the same amount of air as an 80.

What's a Phone Booth? LMAO!!! Haven't seen one of those in years!:D :D :rolleyes:

Like2dive
10-15-2007, 06:48 PM
Lottie

Now I'm confussed. I'm going with this kid:
http://www.youtube.com/watch?v=FnD3RyC7Zj8 He makes his own out of garden sprayers!!!

Papa Bear
10-15-2007, 07:14 PM
Lottie

Now I'm confussed. I'm going with this kid: http://www.youtube.com/watch?v=FnD3RyC7Zj8 He makes his own out of garden sprayers!!!

It really was a "Tank" and I think he was wearing Split-Fins! :D :D Although he will never grow weeds or maybe attract flies! :rolleyes:

lottie
10-15-2007, 07:30 PM
Lottie

Now I'm confussed. I'm going with this kid: http://www.youtube.com/watch?v=FnD3RyC7Zj8 He makes his own out of garden sprayers!!!

now that is good!!! - I didn't see many bubbles..so maybe they made a rebreather?? and what was up with his legs??? that didn't look like anytype of frog kick at all LOLOLOLOLOL :D

acelockco
10-15-2007, 08:15 PM
Wow, that thing is about as useful as a 1.7cu.ft. spare air at 220 feet!

Papa Bear
10-15-2007, 08:18 PM
Wow, that thing is about as useful as a 1.7cu.ft. spare air at 220 feet!

But you can't spray the weeds with a spare air! :D :D :rolleyes: