My 1st Diving Problem Ever!

[Cave Diver]

If you read on, i said im not a full DIR diver to a degree. Thanks for posting though Cave Diver.
Cheers

In all fairness to you, there are no *degrees* of DIR diver. Either you are, or you're not. I don't want to start a whole DIR vs. Non-DIR arguement here, there are plenty enough threads around for that. I'm just trying to gently point out to you that someone that truly follows the DIR style of diving would not subscribe to some of the practices that you've mentioned.

If that style of diving is something you want to pursue, you might be interested in the link at the bottom of my signature line.

Good luck and dive safe!

 

[HybridDiver]

The main thing about DIR Style is buddies. I dont have the option of diving with buddies who would like to DIVE Dir, or even dive at all.
Chris

 

[HybridDiver]

I don't think I would be comfortable with a buddy, instant or not, who would pack his gear and leave me in the water if we became seperated. That's not the definition of a buddy, at least as I learned it.

Phil

Not much you can do when both regs are free flowing and you tryed to do a search for your buddie and nothing. Padi teachs you only do a max search of 5 mins and then accent to the top, Less my instructor is on glow thats how I have been taught.
Chris

 

[amascuba]

The main thing about DIR Style is buddies. I dont have the option of diving with buddies who would like to DIVE Dir, or even dive at all.
Chris

Particularly at the recreational level, diving with buddies that have the same type of equipment (DIR style) doesn't make you DIR.

I don't think it was DIR to take a diver that you don't even know on a 100ft dive. You didn't know the experience or skill level of the dive and you and your team mate should definitely be on the same page for a 100ft dive.

I don't think that taking a 100ft dive with such a lack of seriousness is DIR. Did you gas plan? Did you use minimum gas? If you did, then you would most likely have dove in double cylinders or a single high volume tank because of the minimum gas you would have needed to complete a 100ft dive as safe as possible.

Diving in a backplate and long hose doesn't make you DIR. Solo diving doesn't make you DIR. In fact mentioning DIR and solo diving in the same sentence is an oxymoron.

You are definitely a good candidate for a DIR-F class and making excuses as to why you can't take the class doesn't help your stance any.

DIR is a philosophy and a mindset for striving to approach diving in the safest manner possible and from your post you haven't shown that strive. So what makes you DIR?

 

[HybridDiver]

Particularly at the recreational level, diving with buddies that have the same type of equipment (DIR style) doesn't make you DIR.

I don't think it was DIR to take a diver that you don't even know on a 100ft dive. You didn't know the experience or skill level of the dive and you and your team mate should definitely be on the same page for a 100ft dive.

I don't think that taking a 100ft dive with such a lack of seriousness is DIR. Did you gas plan? Did you use minimum gas? If you did, then you would most likely have dove in double cylinders or a single high volume tank because of the minimum gas you would have needed to complete a 100ft dive as safe as possible.

Diving in a backplate and long hose doesn't make you DIR. Solo diving doesn't make you DIR. In fact mentioning DIR and solo diving in the same sentence is an oxymoron.

You are definitely a good candidate for a DIR-F class and making excuses as to why you can't take the class doesn't help your stance any.

DIR is a philosophy and a mindset for striving to approach diving in the safest manner possible and from your post you haven't shown that strive. So what makes you DIR?

One thing i think is funny, is that you guys say going to 100 feet is bad on a single tank. My question is why in AOW they take you to 130 feet on single tank? Why would padi teach AOW on a single tank if it was no safe to dive to 100 feet. So that being said, you guys who say dont dive to 100 feet on single tank should not be saying that. Talk to padi, talk to TDI, talk to any of the other agencies that do AOW and see what they think its safe to dive to 130 feet with single. Thats just my food for thought.
Chris

 

[ianr33]

My question is why in AOW they take you to 130 feet on single tank? Why would padi teach AOW on a single tank if it was no safe to dive to 100 feet.
Chris

What does PADI have to do with DIR?

Do you have any idea what you are talking about?

Are you DIR because you have some black gear??

 

[amascuba]

One thing i think is funny, is that you guys say going to 100 feet is bad on a single tank. My question is why in AOW they take you to 130 feet on single tank? Why would padi teach AOW on a single tank if it was no safe to dive to 100 feet. So that being said, you guys who say dont dive to 100 feet on single tank should not be saying that. Talk to padi, talk to TDI, talk to any of the other agencies that do AOW and see what they think its safe to dive to 130 feet with single. Thats just my food for thought.
Chris

Did PADI teach you about proper gas planning or minimum gas?

Can you tell me how much gas you would need to complete a dive to 100ft for 30 minutes with a minimum gas reserve before you even get in the water?

How much reserve would you need to do an emergency out of gas ascent doing minimum deco from 100ft?

What is your SAC rate?

What was your buddies SAC rate?

I'm a PADI Divemaster and certified with Advanced Nitrox/Decompression Procedures with TDI. I know what both PADI's and TDI's stances are for 100ft dives.

Does that make either one of them correct?

Does that mean that either agency is teaching people to dive as safely as possible?

Does that make TDI or PADI DIR?

Can you answer any of those questions?

 

[divinginn]

welcome to the scubaboard:light:

 

[amascuba]

To help you understand what I'm talking about, here is how I would gas plan a 100ft dive with a 30minute BT.

I typically plan my dive using a .75ft3/min SAC rate. It's typically lower than that, but it fluctuates depending on what I'm doing during the dive and the diving environment.

I know that I'll descend at 60ft/min. and that most likely my gas choice is going to be EAN32%. I know that my ascent rate will be 30ft/min. to 60ft, which I will pause just long enough to control my buoyancy for my minimum deco stops. I will make 1 minute stops (30sec. hold, 30sec. move) stops at 50,40,30,20,10 and depending on how I'm feeling during the dive or if it's a repetitive dive I might make the 20 and 10 foot stops 3minutes each. So I must plan my gas as if I'm going to make the longer stops at the shallower depths.

So here's an estimate of how much gas I will use during the dive:

100ft/4.03ata x .75ft3/min. x 30min. = 90.675ft3 (91ft3)

We'll use an average depth of 70ft for the ascent rate of the dive to 50 ft since we know that the ascent rate is 30ft/min. and that it will take nearly 2 minutes to ascent to 50ft.

70ft/3.12ata x .75ft3/min. x 2min. = 4.68ft3 (5ft3)

50ft/2.51ata x .75ft3/min. x 1min. = 1.88ft3 (2ft3)

40ft/2.12ata x .75ft3/min. x 1min. = 1.59ft3 (2ft3)

30ft/1.90ata x .75ft3/min. x 1min. = 1.42ft3 (2ft3)

20ft/1.60ata x .75ft3/min. x 3min. = 3.60ft3 (4ft3)

10ft/1.30ata x .75ft3/min. x 3min. = 2.92ft3 (3ft3)

91 + 5 + 2 + 2 + 2 + 4 + 3 = 109ft3

109ft3 is just how much gas that I'm estimating that I will use during the dive. That's allot more gas than is in a single AL80 and I didn't even take into account minimum gas. Now lets look at the minimum gas for a dive to 100ft.

The minimum gas is how much reserve that I would need in the event of the worst possible scenario during the dive: My buddy lost his gas supply and is Out of Gas at 100ft at the 30min. mark. When you're stressed, such as handling an OOG emergency, your breathing is accelerated so you will need to account for that. We will use 1ft3/min. for the emergency and we will need to account for two people breathing that rate since you've donated your long hose to your OOG buddy. Let's do the math:

We'll need to spare one minute to recognize the emergency, react, and stabilize the situation before we make our ascent.

100ft/4.03ata x 2ft3/min. x 1min. = 8.06ft3 (9ft3)

We'll use an average depth of 70ft for the ascent rate of the dive to 50 ft since we know that the ascent rate is 30ft/min. and that it will take nearly 2 minutes to ascent to 50ft.

70ft/3.12ata x 2ft3/min. x 2min. = 12.48ft3 (13ft3)

50ft/2.51ata x 2ft3/min. x 1min. = 5.02ft3 (6ft3)

40ft/2.12ata x 2ft3/min. x 1min. = 4.24ft3 (5ft3)

30ft/1.90ata x 2ft3/min. x 1min. = 3.80ft3 (4ft3)

20ft/1.60ata x 2ft3/min. x 1min. = 3.2ft3 (4ft3)

10ft/1.30ata x 2ft3/min. x 1min. = 2.6ft3 (3ft3)

9 + 13 + 6 + 4 + 4 + 3 = 39ft3

That's nearly 40ft3 of gas that we will need to reserve just to handle an emergency!

So to complete the dive as safe as possible I would need 148ft3 of gas. An AL80 is really 77ft3 (77.4ft3 if you want to get really picky). So an AL80 at 3000psi (77/3000 = .025) has .025ft3 of gas per psi or 2.5ft3 of gas per 100 psi. If I'm going to do a dive to 100ft, I'm most likely going to do it in a minimum of double AL80's. That will give me 154ft3 of gas, which is enough gas to do the dive as safe as possible.

How many tank manufactures do you know of that make scuba tanks with enough volume to do that dive with a single tank and have enough gas to do the dive as safe as possible?

 

[rongoodman]

The above all makes sense except that you have included gas for your ascent in two places, in your original dive plan and again in your minimum gas calculation.