Terminology: "Required Safety Stop"

[ianr33]

All of this makes sense. But it does not address the question: Why don't they call it a "decompression" dive when they "require" a stop? Once the stop becomes required, it moves from being a safety stop to a decompression stop. No?

Its marketing,not truth.

Maybe there should be a card for "Required Safety Stop Diver" ? Surprised they miised that one

 

[Walter]

The terminology "required safety stop" is bad, but so is "no decompression dive".

I can see how some might think so, but in reality, "no decompression" is merely short for "no staged decompression stops." OTOH, a "required safety stop" is a "staged decompression stop."

 

[daniel1948]

Back in this thread, specifically this post, Blackwood says

There's no inconsistency.

The difference is that said "required" safety stop isn't required to satisfy the decompression model, it's to satisfy the author of the table annotation (and likely the lawyers turning the screws).

If Blackwood is correct, it answers the question. The closer you get to the NDL limit, the greater the risk (as there's always some risk no matter what) and PADI has decided to "require" a greater margin of safety than the decompression model used to derive the table.

 

[eponym]

One of the local dive shops is SSI. I am going to ask if they have an SSI equivalent of the RDP, and compare the numbers.

Here are the SSI no-deco times for each depth:

[table 0 0 2]f.s.w.|minutes
040|130
050|070
060|050
070|040
080|030
090|025
100|020
110|015
120|010
130|005[/table]

Unlike PADI, the SSI tables make no reference to a "required" safety stop, no matter how close to the no-deco time limit you get. But SSI NDLs are ten to five minutes less than the PADI NDLs.

-Bryan