Coming back with TOO MUCH air??

[beaverdivers]

We use rx7DIVER's idea of using a transfer whip to fill pony bottles between dives.

Just think of all the money you could make.

Of course, we do it for free because we believe that it is an intelligent decision to go down with a FULL tank.

We don't SCUBA dive to save money.

When I was in college, I washed dishes to make enough money for tank fills - cost in the 70's, $3 -$5.

You may want to see if McDonalds is hiring!

Or as I mentioned before a dive shop or boat. However, you may make more money washing dishes.

Also, Free diving, the air is Free.

Good Luck and Good Diving!

 

[OBXDIVEGUY]

It might be a little bit for you to drive, but Fill Express in Pompano charges by the cubic foot, not by the tank.

 

[dmoore19]

How about trading the 2 80s for larger single tank, HP100 or HP120. Even if only filling to 3000psi you would still have 12CF more gas in the 100 or 30CF more in the 120. That will give you enough air to do 2 dives like the ones you are doing with 1 tank and still have too much air. You would then only have to fill 1 tank and you would only have 1 tank to pay for visual inspection and hydro, thus saving you money.

 

[ermaclob]

ermaclob, everything seems simple, until it isn't.

If you are slinging a bottle with a gauge on it, you've met some of my objections. But I'm still not happy with the idea of breathing your backgas down to nothing and switching to the auxiliary bottle as a matter of course. Suppose you breathe that 80 on your back down, and you go to your pony reg, and the diaphragms gotten folded and the reg is now breathing extremely wet. You don't have enough gas in the 80 to get back to the boat, and your auxiliary supply isn't functional.

Yes, I can come up with "Little House on the Prairie" nightmare scenarios to make ANY setup seem unwise, but the basic principle of using the smallest gas supply up and leaving the bigger one as the reserve is pretty well respected in the technical diving community, because Murphy loves divers, and it's always best to leave him the fewest chinks to worm his way into your plan.

It sounds as though you have decided that your strategy is one you are going to use, so I hope it works well for you, and you don't run into any problems with it. I wouldn't do it.

i dont know if you fully understand, i plan to return to the boat with no less than 500 psi on my back, if in the event that i get to 500psi and im not on the boat, then i will use my pony to continue on to wretch the boat. 500 psi is at least to me still quit a bit of time underwater. say ~20 min. at that point it is my reserve and that will in tern be used to get safely back to the surface in the event that the pony fails. i am not saying that im going to go continue my dive after i hit rock bottom on my back tank.

yea, i understand that the technical diving people most likely all follow that rule, but there doing technical diving, 130+ feet, crazy **** compare to what im doing. if one of those guys messes up they probably die. if i mess up, just calmly surface, its shallow water. important to be safe don't get me wrong, but theirs always some leeway to something in cretin situations


HAHAHA, i just had a thought after reading the Murphy law thing. To contract Murphy law, All i need to do is encourage the one exemption of the law. which would be to have bad stuff happen on purpose. that way im in control of the bad stuff and am ready for it. this in tern does NOT bring more bad stuff. that is y its the exemption of the rule, Or at least this is what some of those rational studys people was telling me one time in school.

=/ i really dont know

 

[rx7diver]

How about trading the 2 80s for larger single tank, HP100 or HP120.

dmoore19,

I'm not so sure this is a good idea here. The OP is a newish, young diver who does both shore dives and boat dives in Florida. I assume he wears either a 3 mm or a 5 mm wetsuit. A HP120 is quite negatively buoyant when full, which might compromise two of the fundamental emergency procedures discussed in basic scuba (i.e., establishing positive buoyancy at the surface by dropping one's weightbelt, and performing an emergency swimming ascent with a full cylinder and loss of BC buoyancy perhaps by dropping one's weightbelt at depth if necessary).

In addition, I do not find shore diving an HP120 a pleasant experience. It is very heavy (to me) out of the water.

Finally, surface swimming (e.g., to/from shore) either an HP100 or an HP120 while wearing a thin wetsuit is not nearly as comfortable (to me) as surface swimming either an Al 80 or an old-style Steel 72.

FWIW,

rx7diver

 

[irishsquid]

Just a question, " When you plan a road trip do you worry about 1 Gallon of gas? ".

A gal. of gas cost about the same as a tank fill.

The difference is when you run out of gas in your vehicle, you can get out and walk.

However, when you run out of GAS in your SCUBA tank(s) it could become a bigger issue.

As a college student you probably ride a bike.

Why not just free dive the 2nd shallow dive?

When you go to get gas after a road trip, and top off your tank with, say 5 gallons. Do you want to pay a full tank price of $80 dollars for those 5 gallons ?
I think that is more what the OP had the problem with. I do get your point though.

 

[spectrum]

I often have the situation of coming back from a dive with enough to theoretically repeat with the balance. IMO it's not worth messing with penny pinching. Anything you do means more gear, more money, more lugging. On top of that your situation may change. You limiting factor may resolve and then you can do justice to that cylinder with 75-90 minute dives. Write off as a transitional situation.

Pete

 

[beaverdivers]

IrishSquid, you are correct.

Back in the 70's a gal of gas cost .25 cents, it may reach $5/gal this spring. That is 20X the cost, so a tank fill should cost 20 X $4 ( ave. price for a tank fill in the 70's ) = $80

Fortunately, due to the fact LDS are not greedy and some not too bright, a tank fill is close to the same price as 40 yrs. ago!

If you can NOT afford to fill your SCUBA cylinder, then FREE diving is an excellent choice.

Furthermore, get a part-time job that pays 2012 wages and get your tank filled at 70's prices.

Back when I was washing dishes I got payed under $3/hr and still was able to pay for the $4 fill.

It was well worth the hour and a half that I had to work to be underwater for an hour!

 

[irishsquid]

IrishSquid, you are correct.

Back in the 70's a gal of gas cost .25 cents, it may reach $5/gal this spring. That is 20X the cost, so a tank fill should cost 20 X $4 ( ave. price for a tank fill in the 70's ) = $80

Fortunately, due to the fact LDS are not greedy and some not too bright, a tank fill is close to the same price as 40 yrs. ago!

If you can NOT afford to fill your SCUBA cylinder, then FREE diving is an excellent choice.

Furthermore, get a part-time job that pays 2012 wages and get your tank filled at 70's prices.

Back when I was washing dishes I got payed under $3/hr and still was able to pay for the $4 fill.

It was well worth the hour and a half that I had to work to be underwater for an hour!

Yep; my LDS and local dive hole still charge only $5 for a fill. Ahhh, the 70s, I somewhat remember those days. I used to get gas for my first car at 21 cents a gallon at the Kayo. To fill and top off my Harley costs as much now as what I used to put in my truck to get to work for a week, just a few years ago.

 

[elan]

You are playing quite dangerous game when you start doing "optimizations" trying to reuse every cubic foot. Every dive you have to apply different gas planning. One dive you have the full tank, the other less then a full and you rely on the pony. This is where the stuff easily goes north.

Besides your needs you need to account for the gas for your buddy.
In your scenario when you switch back and forth from back gas to pony does your pony have 2 regulators so you have a reserve for your body?

At that stage I would just stick to the established protocols without doing any inventions. Just get the full tank and dive..