POP QUIZ: How deep do you gotta be....

[The Chairman]

but with DUAL 100# bladders... Hey Mikey, we be diving with the rig that has gone the deepest (over 1000 ft) on OC and the diver still surviving. I bet they were bungeed too! That would be just TOOOOOO cool!!!

 

[Steel95s]

I'll have to add my two cents worth on this one. As you can see :crush: I've crunched the numbers. I agree with NetDoc and solodiver's numbers. After all, I have the numbers right here. :deal:

 

[padiscubapro]

Originally posted by Tom Vyles


The open circuit scuba depth record was recently broken. Read Aprils edition of Skin Diver. Side note, he was using Apeks regs and an OMS wing. (Non bungied I would bet)

Tom

from what I have read from various sources when the 1010 ft record was set he used oms 100lb wings and oms lights and abysmal software and regs were used..
I also remember seeing letters from john to both obs and abysmal that were posted.

 

[Texas Tek-diver]

Hey ya rustyscubatool,

You asked, "what is the deepest anyone has ever dived on scuba?"

John Bennett on Nov. 6, 2001 (Tuesday) made a dive to 1010 feet which took 9.36 hours at Sabang Beach, Philipines (these are approximate numbers). He was using an OMS BC with OMS cylinders on APEX100 regulators wearing stage bottles on each side.

Want any more info?

 

[tomcat]

Originally posted by SaltyWhale
Hi Folks....

And we do have to knock off 1atm from the surface regardless of absolute / gauge pressure. An empty tank at the surface still contains 1atm not 0atm.

Cheers

Hey SaltyWhale,

I'm confused now.

By your argument, it seems that we don't have to knock off 1 atm from the surface. When the tank is "empty" at the surface, the depth gauge reads 0 meters and the spg reads 0 psi correct? Which means that the pressures will also be balanced when the tank is 10m under water with the spg indicating 1 atm of air in the tank.

tomcat

 

[SaltyWhale]

Hi tomcat

By your argument, it seems that we don't have to ..........

By my point of view I'd rather say.


However, you are right, it seems a lil' confusing. Let me try storming my brains (refer to some theory manuals) over it and get back to you when "EUREKA" is achieved.

Cheers..!

 

[SaltyWhale]

Hi tomcat


You are right.....we need not take of 1 atm from the amount.

 

[roakey]

Originally posted by NetDoc
"Sealed" noted by psis, is NOT a differential value but a "true value". It uses an internal reference to measure the internal pressure of a vessel. A sealed gauge may or may not be absolute. If it reads 3000 psis the pressure may very well be 3015 psia (depending on the reference). HOWEVER at depth (6735 fsw) it will STILL read 3000 psis. The reading does NOT change with ambient pressure.

Look Pete, I'm getting pretty tired of arguing with you so I'll make this short and sweet.

I had never seen the psis nomenclature before and the differentiation between psig and psis makes sense.

You're right, I stand corrected.

Roak

Ps. Bet that didn’t end up where you thought it was going

 

[roakey]

Originally posted by TexasMike
Please also understand that the instructor was not intending to provide us with "gospel" information. He was just trying to liven us up a bit with a "spur of the moment" thinking question during a long class session.

Let me explain why I held onto this like a bulldog. Many years ago in Advanced Open Water an instructor “threw out” a question in very much the same manner. It was along the lines of “How much does a steel cylinder, such as a 72 swing from full to empty versus an AL80 and when does the swing occur?”

Next class I was the only student that found the question interesting enough to work out, a 72 swings approximately 5.5 pounds and an AL80 swings approximately six pounds linearly through the dive. Once I sat down I realized that the problem was fairly simple, the cylinder’s volume doesn’t change significantly as is evidenced by the small burettes used to measure cylinder volume changes during a hydrostatic test, so the only variable is air weight. My CRC helped me figure out that that’s about 1 pound for every 13 cubic feet, giving me my answers.

Nope, a steel does not swing at all, and an AL80 does swing about 6 pounds, but that happens during the last 500 psi; it doesn’t change buoyancy at all during the first 2500psi. At least according to this (PADI) instructor. We went at it tooth and nail, physics on my side and an “I’m the instructor, I know more than you do” mentallity on the other. He tried every argument from authority he could think of when finally he stated flatly that I was wrong and there would be no more discussion.

That one event started me realizing how much misinformation surrounds cylinders and their characteristics, and has kept me interested in the topic for so many years.

So a follow-up question here is did the instructor say, woops you’re right, it IS 6,735 feet, or did he blow the correct answer off trying to save face?

Roak

 

[Daniel Joubert]

WHO THE HELL IS GOING TO BE AT >6700 FT IN ORDER TO OPEN THIS BL-ODY CYLINDER ANYWAY ???!!!!???