Quiz - Recreational Dive Planner™ - Max Time

[boulderjohn]

This is true. But that desire was not embedded in the RDP table.

Thanks for the explanation. This quote was exactly what I was saying above. They had multi-level diving as a goal, but the RDP table does not enable it. That was never intended for the RDP--that was why they made the wheel. My point was that you cannot use the RDP accurately for multi-level dives. Because they always had multi-level diving in mind, if they thought the RDP could do it, they would not have gone on to make the wheel.

I learned to use the wheel for my DM exam, and I learned it again for the instructor exam. The instructor exam showed a problem with both the wheel and the kinds of exams they did. On one of the wheel questions, I came up with an answer that was not one of the choices; it was precisely in between two of them. I did it again and again and again. I finally chose one of them, and it was wrong. IN his review, the instructor did it with his wheel and got the correct answer. I handed him my wheel and had him do it. He came up with the answer I did. My wheel was perfectly calibrated, but it gave a different answer from his.

Of course, the real problem is that in real life, it does not matter. Both answers were close enough for diving. It only matters in multiple choice tests.

 

[BlueTrin]

I never saw that PADI wheel, What´s this calibration that is required ?

 

[boulderjohn]

As for me, for recreational diving, I run a GFhi of 85, and I usually like to get my SurfGF below 70. If things are running late, I will go up at 75.

 

[boulderjohn]

I never saw that PADI wheel, What´s this calibration that is required ?

The wheel had different parts that turned around each other, and you had to note where a line crossed a pressure group indicator. The difference could be the width of a hair. There was a circle on one piece and a dot on the other. If when you lined them up, the dot was not in the circle, you were not calibrated. I assume that even though mine was calibrated, it was just far enough off that it missed a line it was supposed to touch to get the right answer.

 

[tursiops]

My point was that you cannot use the RDP accurately for multi-level dives.

But, as Duis (1991) points out, you CAN use the RDP for multi-level dives, but you have to take into account the same two things that the Wheel takes into account: your next level must be sufficiently shallower, and you must reduce the NDL for that new depth from what is on the RDP.

Am I not saying this clearly?

 

[boulderjohn]

But, as Duis (1991) points out, you CAN use the RDP for multi-level dives, but you have to take into account the same two things that the Wheel takes into account: your next level must be sufficiently shallower, and you must reduce the NDL for that new depth from what is on the RDP.

Am I not saying this clearly?

Well, this is the point that I admit I had never before heard of Duis (1991). Having read through the other thread you started, I am simultaneously glad I had not heretofore sullied my mind with it and sorry I have experienced it now.

 

[Blackcrusader]

I never used that, it’s funny how it has been made to look like a calculator

Here is the latest Chinese version of the Shearwater Perdix...

 

[Blackcrusader]

So, I will give this a shot. I dive at GF high of 95 to reasonably match my DSAT. I run my SurfGF down to the mid to high 80s before I surface. This only comes into play when I have closely approached no NDL

I run my Perdix is OC Tec mode and GF 45 95. This means you have to arrange your own safety stop the device won't baby sit you. I usually am off gassing at around 5m for 10 or more minutes on reefs where I dive anyway and I love the large DECO CLEAR message that come up when you have done the safety stop. Then you get CLEAR plus the amount of time cleared.

 

[boulderjohn]

I run my Perdix is OC Tec mode and GF 45 95. This means you have to arrange your own safety stop the device won't baby sit you. I usually am off gassing at around 5m for 10 or more minutes on reefs where I dive anyway and I love the large DECO CLEAR message that come up when you have done the safety stop. Then you get CLEAR plus the amount of time cleared.


View attachment 585224

If you get a Deco Clear message, then you have not done a safety stop. You have done a decompression stop because you violated NDLs on the dive.

 

[Edward3c]

If you get a Deco Clear message, then you have not done a safety stop. You have done a decompression stop because you violated NDLs on the dive.

But John, your assuming people actually know what their computers are telling them.