Is a spade a spade

[captain]

The PADI recreational dive planner makes a 3 minute 15' safety stop "mandatory" on NDL dives below 100 feet and anytime when getting within 3 pressure groups of the NDL.

When a stop becomes mandatory should it still be called a safety stop or should it call a decompression stop or something else and if the stop is mandatory is it still an NDL dive.
Does missing a mandatory safety stop on the PADI table put a diver at greater risk than a diver skipping an optional safety stop on another table.

Opinions?

Mine is that calling it a safety stop is a bit misleading since by original definition a safety stop was recommended but optional and is optional on other tables.

[Blackwood]

A "decompression stop" is required by the model. A "safety stop" is not.

It's not misleading since the model on which the RDP is based generates no-stop times (regardless of how the hard copy is annotated).

[rstofer]

This has been debated endlessly - to no resolution.

Many of the long time divers will say that NDL is just what it says it is: No Decompression Limit. These 'mandatory' or 'recommended' safety stops should NOT be required.

OTOH, PADI made up the tables and they did the testing. It might be unwise to simply blow off their recommendations. But it is also PADI that creates this mess because other tables don't require ANY 'safety' stops and are quite clear about deco stops. NAUI tables come to mind...

But NAUI changed their tables in 1989 to move from a 60 fpm ascent rate to 30 fpm. They also RADICALLY changed how repetitive dives work out. There are examples of perfectly acceptable PADI repetitive dives that simply can't be made with the current NAUI tables.

I'm not much on the 3 minute 15' stop. I don't recall having ever made one. But I started with the 1987 NAUI tables and I still tend to think in those terms.

I think a diver needs to stand on one side of the river or the other. Straddling the thing will not be satisfactory. So, if a diver wants to use PADI tables, they should, in my view, use them EXACTLY the way they are supposed to be used including the 'mandatory' no-deco-limit 'safety' stops.

Then again, there are rumors that PADI will be giving up on tables and this whole debate goes away. Besides, nobody actually uses tables. They simply buy a computer and hope for the best.

Richard

[iztok]

Then again, there are rumors that PADI will be giving up on tables and this whole debate goes away. Besides, nobody actually uses tables. They simply buy a computer and hope for the best.

I use the tables when I do the planning. Is there anything better to use to plan multiple dives to different depths a day?

[Blackwood]

OTOH, PADI made up the tables and they did the testing. It might be unwise to simply blow off their recommendations.

The recommendation of a "mandatory safety stop" came as a result of testing?

I use the tables when I do the planning. Is there anything better to use to plan multiple dives to different depths a day?

There are a myriad of tools available, including tables, PADI's wheel and eRDPml, most dive computers, desktop software packages, ratio deco/MDL, etc..

[Michael_Lambert]

I use the tables when I do the planning. Is there anything better to use to plan multiple dives to different depths a day?

As said there are many options out there. I prefer like many to use Vplanner.

Some days you just don't feel 110% so its nice to be able to adjust your conservatism in order to make up for days your not 110% or if you know your going to be working it a little harder than normal.

Programs like this also work well when going away for a weekend or doing a couple of days in a day to ensure you have plenty of Gas, as you can plug in your details and it will spit out how much of what gas you should consume on that dive.

[ptyx]

I use the tables when I do the planning. Is there anything better to use to plan multiple dives to different depths a day?

I find software a lot more convenient than tables. Dragging a laptop on the dive boat is no longer required if you have a smart phone or PDA.

On the iPhone: iScuba Plan is great for NDL diving, iDeco works really well for more complex dives, and there is a VPlanner as well which I haven't tried because of the cost (and is probably too advanced for what I need).

[iztok]

I find software a lot more convenient than tables. Dragging a laptop on the dive boat is no longer required if you have a smart phone or PDA.

On the iPhone: iScuba Plan is great for NDL diving, iDeco works really well for more complex dives, and there is a VPlanner as well which I haven't tried because of the cost (and is probably too advanced for what I need).

Anything for blackberry?

[Michael_Lambert]

Jdeco is available for Blackberries.. I use it once in a while.. Prefer V planner but it works in a tight squeeze.
JDeco - Dive Decompression Software for JAVA Mobile Devices (Buhlmann and VPM-B) (http://www.jdeco.de/)

[rstofer]

The recommendation of a "mandatory safety stop" came as a result of testing?


I wouldn't know... I do know that PADI actually did some testing. But, as all they are asking for is a 3 minute stop at 15', why not just follow the directions?

I understand the incongruity of mandating a safety stop for NDL tables. But the debate is pointless. Either a diver will opt on the side of caution and follow the directions, or they won't.

Maybe they'll get hurt; maybe they won't.

A lot of people make a routine 3 minute 15' stop anyway.

But this safety stop is more likely related to PADI allowing a 60 fpm ascent rate than anything else. NAUI backed away from that about 20 years ago when they changed to 30 fpm. Hence no safety stop for the NAUI tables. But then, they didn't have safety stops when they used 60 fpm either.

Besides, nobody takes their tables underwater anymore. How would they know if they were within 3 pressure groups of the NDL? Just make the 3 minute stop and don't worry about it.

In the old days, I wrote the adjusted NDLs on a slate before every dive. With my depth gauge and dive timer, I knew exactly where I was. If I overstayed, all I had to do was pull out my NAUI tables and see what deco stop was required. Today there is no way in he** I could read those tables without my glasses.

My computer takes care of all this stuff.

Richard

[dseiden]

would the apps listed for the iphone be available on the ipod touch?

[AfterDark]

Sounds like what I did for years anyway only at 10' instead of 15'. Whats old is new again.

[Michael_Lambert]

would the apps listed for the iphone be available on the ipod touch?



Yup as long a you pay for the itouch upgrade, i think i paid like $5 for the upgrade allows you to use the app store and install the Ideco Pro which is nice to have. Pick up a housing for the itouch and you can toss it in your pocket and take it diving :D

[Peter Guy]

I did a workshop for some of our dive staff recently and one of the modules was Decompression Theory and Practice. Part of the discussion was:

Every dive is a decompression dive.

One of the staff had a hard time wrapping her mind around the concept in large part because "Decompression" meant "Staged Decompression" to him. Another participant jumped in and suggested that I say:

Every dive is an On-gassing and Off-gassing dive.

This he could understand and get -- whether we call it an "No Decompression Limit" diving, "Minimum Decompression Diving" or just "Diving" -- in every dive you do on Scuba, you on-gas and you off-gas. The key is coming up with a plan FOR YOU that works and lets you go home feeling fine.

There are any number of ways to get there -- PADI RDP, Minimum Deco, Riding Your Computer -- whatever. But just remember, you will ALWAYS need to off-gas. The real key is where you want to do it -- in the water or on the surface -- and how much where.

[Blackwood]

I did a workshop for some of our dive staff recently... Part of the discussion was: Every dive is a decompression dive.

One of the staff had a hard time wrapping her mind around the concept in large part because "Decompression" meant "Staged Decompression" to him.

I find it a bit... worrisome that dive staff (who is somehow both female and male :D) struggled with that concept. What did s/he think was the purpose of dive tables/computers, and how did s/he adequately and appropriately instruct others?


Every dive is an On-gassing and Off-gassing dive.
This he could understand

Hmm... I'd go with:

What's the pressure at the surface? What's the pressure at x feet? What happens to the pressure as you ascend from x to the surface?

[Peter Guy]

Marc, I sometimes "mix genders" to protect the guilty!

S/he probably does understand the reasons for the tables, computers, etc. but s/he has been so "brainwashed" with the idea of "No Decompression Limit" dives and it was hard to switch over to the idea that "Every Dive Is A Decompression Dive." To him/her, there was a bright line between "NDL" dives and "Deco" dives.

I think (I hope) that bright line has been significantly blurred!

[divin'dog]

The PADI recreational dive planner makes a 3 minute 15' safety stop "mandatory" on NDL dives below 100 feet and anytime when getting within 3 pressure groups of the NDL.

When a stop becomes mandatory should it still be called a safety stop or should it call a decompression stop or something else and if the stop is mandatory is it still an NDL dive.
Does missing a mandatory safety stop on the PADI table put a diver at greater risk than a diver skipping an optional safety stop on another table.

Opinions?

Mine is that calling it a safety stop is a bit misleading since by original definition a safety stop was recommended but optional and is optional on other tables.

Check out this article on DAN's site:
DAN Divers Alert Network (http://www.diversalertnetwork.org/news/Article.aspx?newsid=514)

While it talks about deep stops, I think it's relevant to why safety stops are recommended or are becoming "mandatory"... Ascent rates are part of the equation.