Minumum surface interval calculation using RDP

[PaulNewcastle]

Dive to 18M for 40mins (puts you in pressure group P)

then Dive to 14M for 60mins

whats the minimum surface interval, and how do you calculate it on RDP?

Cheers

[Lazlo]

Minimum surface interval is the minimum time you need to spend on the surface so that you can do the second (repetitive) dive without incurring a decompression obligation - i.e. a "no-stop" dive.

- Turn over rdp to table 3

- Find the row that is at least 14m and look across until you get to an allowed bottom time of at least 60min.

- Look up to give a pressure group. This is the pressure group you need to be when you hit the water on the second dive.

- Turn over rdp again to table 2

- Read across from pressure group P (from your first dive) and see what the minimum time is to get from P to the pressure group you found above.


Phew!


p.s. I hope you're not in the middle of your final exam!

[PaulNewcastle]

28 mins?

Final exam is tonight, i'm doing KR5

Thanks very much (if 28 mins is right )

[dlegros]

28 mins?

Final exam is tonight, i'm doing KR5

Thanks very much (if 28 mins is right )

So that'll be question 6 then - enjoy question 7

An easy way to remember which of the table 3 numbers you want is to remember that "Blue you can do".

Dom

[Lazlo]

I don't know if that is right or wrong - these instructions are from memory!

You can check the result by going throught the process in the "normal" direction plugging in 28mins as a surface interval. If you've done it right then you should end up in a black box, at the bottom of the 14m column on table 1 - which, as you know, means that you have used up ALL of your available no-stop time.

And THAT would mean that you'd need an extended surface interval for a theoretical 3rd dive

Good luck on your exam. If you've any issues I recommend you go through the Instructions for Use booklet again.

[turbanator]

some more examples
r
P

[PaulNewcastle]

So that'll be question 6 then - enjoy question 7

An easy way to remember which of the table 3 numbers you want is to remember that "Blue you can do".

Dom

Do i have to get in the Delorian and go back in time for the surface interval in question 7?

[Lazlo]

Do i have to get in the Delorian and go back in time for the surface interval in question 7?

Think about it

[Lazlo]

some more examples
r
P

Does anyone do them in meters?

Could just think of my own I suppose.... mutter ... whinge ...

[PaulNewcastle]

My trouble is i think too hard

Dive to 20M for 29mins

then

to 14M for 39

= MSI of .......

__SCRATCH THAT__

I keep getting PG P for my 2nd dive and M for my first, these two don't intersect on table 2