Padi RDP

ticfrd · **Joined:** Sun Nov 23, 2008 6:48 pm **Posts:** 8

Hello
I don't want you to all cheat and give me the answers but .....

A chapter 5 review question

What is the minimum surface interval required between a dive to 20m/70ft for 29 minutes followed by a dive to 14m/50ft for 39 minutes?

I worked it out and theres no cross over on table 2 (metric)
and it appears there is no minimum surface interval for this dive so I think "dumb question, or I must be a thicky"

On the imperial tables I get 4 to 8 mins.

The question before this one is worse answer metric = 00:28 imperial is 01:12

Why the big difference in times? is it because 20m is actually less than 70 ft ?

plumb bob · **Posted:** Tue Dec 16, 2008 6:38 pm

I'd try and answer ya but I don't have a RDP handy.... Anyone able shed some light here?

Dazzzler · **Posted:** Tue Dec 16, 2008 6:51 pm

My girlfriend did that exact question on Sunday night on the e-learning course which I'm guessing you are also doing...

The letters don't line up, 9from memory M across and P up) and they didn't when I did my open water 3 yrs ago.

The answer is... wait for it.... 00:00. Stupid trick question that serves no purpose other than for you to question what you have learnt thus far....

GO PADI GO!! PUT ANOTHER DOLLAR IN WOULD YA

ticfrd · **Joined:** Sun Nov 23, 2008 6:48 pm **Posts:** 8

Thanks for that guys, seems I may not be as thick as first indicated.
Frustrating question for a new guy though, seeing as its a trick question.

But can you shed more light on why the big difference in times between imperial and metric depths in the same question?

In the example 20m/70ft, 20m is 20m but 70ft is actually 21.3m and would be rounded up to 22m.
And 14m/50ft...... 14m is 14m but 50ft is 15.2m and would be rounded up to 16m.

Could this be why there is an imperial answer but not on the metric tables.

Just glad WE live in a metric society.

plumb bob · **Posted:** Wed Dec 17, 2008 7:13 pm

If we didn't live in a sane (metric) society then then we'd live in Liberia, Myanmar or the United States. :roll:

I have included a handy map reference of those backward places best avoided...

Red = stuck in the middle ages....

Flipper · **Posted:** Sat Dec 20, 2008 1:38 pm

Nothing wrong with imperial measurements;

Wikipedia wrote:

Mars orbiter
The use of two different systems was the root cause in the loss of the Mars Climate Orbiter in 1998. NASA specified metric units in the contract. NASA and other organizations worked in metric units, but one subcontractor, Lockheed Martin, provided thruster performance data to the team in pound force seconds instead of newton seconds. The spacecraft was intended to orbit Mars at about 150 kilometers (93 mi) altitude, but the incorrect data meant that it probably descended instead to about 57 kilometers (35 mi), burning up in the Martian atmosphere.

...right, I'm off for a pint

Packhorse · **Posted:** Sat Dec 20, 2008 2:02 pm

A standard pint or a US pint?

Flipper · **Posted:** Sat Dec 20, 2008 9:10 pm

...to simplify things I was going to create my own pint standard. The nice thing about standards is that there are just sooo many to choose from

tazbubz · **Posted:** Sun Dec 21, 2008 5:08 am

isn't a standard pint like 470 mls or something? found that interesting as the pint glasses in the pubs where between 500-600ml

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