RDP Plus – Those grey and black boxes

Understanding the color codes on the DSAT RDP as they relate to depth
and time. Let’s pull out and dust off that RDP and begin on Table 1.

Table 1, the No Decompression Limits and Group Designation Table
contains a bit of information. You have Pressure Group Designation
running up and down the left side (The A – Z characters), Depths (found
across the top of table 1), Times (the numbers found in the blue/white
boxes), grey and black boxes.  Let’s focus on the grey and black boxes.

Flip the RDP so you are viewing the side with Table 3.  Locate the
paragraph reading Safety Stops. Let me quote the section.

“Safety Stops  – A safety stop for 3 minutes at 15ft is required any time
the diver comes within 3 pressure groups of a no-decompression
limit, and for any dive to a depth of 100 feet or greater.”

Taking the statement above while looking at the table 1 of the RDP
you find at the bottom of the 35, 40, 50 – 90 foot column, the last
three boxes (times) before/above the no decompression time are
shaded grey.  It is these grey boxes with times the above quote is
referring to. Also note the depth columns of 100, 110, 120, 130 &
140 times are all shaded out.

It is advisable to make safety stops during every dive. You might
as well if you still have air to support it. Who knows what you might
see.

Larry Davis

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