Learning the wheel

[BarryNL]

The theory and use of the wheel is straightforward enough, but I notice that most of the time I get slightly different answers to the ones in the instruction book (a minute more/less or a pressure group higher/lower).

Another DM candidate on my course has exactly the same issue. Is this simply the problem that all wheels differ slightly (even if the alignment dot says it's OK).

Do you need to use the wheel in exams and get the same answer as PADI got with their wheel, or is this not really a problem?

 

[GA Under Water]

If I remember correctly Those are fill in the blank and your instructor makes allowances for differences in the Wheel.

 

[PlayaCountryBoy]

I too have noticed discrepancies between Wheels I have used and use. I do check my students work with the Wheel they used. If it's the answer I would have choose, going by the way the Wheel functions and operates, then I agree to their answer being correct. C'mon PADI, make 'em the same...can't be that hard.

 

[RJP]

Was working with a class a few weeks ago and had the same problem. I attributed most of the discrepancies to slight variations as to how people were holding/aligning/viewing the wheel.

 

[SharkDZ]

I still use the wheel (and tables for that matter,) but I think PADI shoud develop an Ewheel.

 

[Jim Lapenta]

That's what the alignment dots are for. You need to calibrate your wheel to the tables as well. Once you do that note the position of the dots and where they line up with respect to the numbers. My wheel may indicate a desired group at dead center on a number, yours may be to the left or right of it. I personally like mine and find it faster than tables.

 

[dartref]

I love the wheel, but have had the same problems even with the wheel being "calibrated" correctly. There is still a slight variance among calibrated wheels due to the small allowance in the little window. It was also my experience that an incorrect answer on the test will be given credit if the instructor gets the same answer using the same wheel.

 

[pwl]

during my course, the wheels my course buddy & i used were slightly off - enough to give a slightly different answer either way. there was a degree of parallax error involved - such that, if you knew what the answer was "supposed" to be, you could adjust the way you looked at the wheel (where the intersection happens) to get the "right" answer.

if in doubt, be conservative.

 

[AndyA]

In small print on the answer sheet there was a statemnt that indicated - if the answer is within 2-3 minutes the answer is correct

 

[BarryNL]

In small print on the answer sheet there was a statemnt that indicated - if the answer is within 2-3 minutes the answer is correct

Hmm, that's all very well, but calculating minimum surface intervals can easily put you 20 mins or more off if the discrepancy gives you a different pressure group.

I'm just happy I use DecoPlanner in real life