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Largo
06-11-2008, 21:18
I'm not sure where this should go.

NAUI has revised its guidance on precautionary decompression stops. The new guidance is based on the publication Undersea and Hyperbaric Medicine 2007; 24(6):399-406, by Bennett et al.

NAUI recommends that, for dives in excess of 40 feet, that divers make a 2 to 3 minute stop (with 2.5 minutes being optimum) at a depth that is half that of the deepest depth reached during the dive, and make a precautionary stop in the 10-20 feet zone for one minute before returning to the surface.

Makes sense to me.
Are the other agencies making similar recommendations?

Geoff_T
06-11-2008, 21:26
don't know but it makes more sense than just doing one at 10-20 ft. Though depending on depth and time I would think you would at least want to stay longer on your seccond stop, if not both.

chinacat46
06-11-2008, 21:29
I haven't heard anything from PADI but they are usually very slow to adopt new ideas IMO. A minute stop at 15 feet would play havoc on my dive computer. Would still have to do a 3 min stop there to keep it from going into error mode.

Largo
06-11-2008, 21:34
I didn't think of that.

Can you reprogram an IQ-700?

Geoff_T
06-11-2008, 22:12
I haven't heard anything from PADI but they are usually very slow to adopt new ideas IMO. A minute stop at 15 feet would play havoc on my dive computer. Would still have to do a 3 min stop there to keep it from going into error mode.


Like I said before it seems to me like you should still do a 3-5 minute stop at 15 even if that is more conservitave. I don't think you are doing anything unsafe by stopping deeper but why abandon the current proven method. Just add the extra level of a seccond stop.

IndyDiver
06-11-2008, 22:34
I haven't heard anything from PADI but they are usually very slow to adopt new ideas IMO. A minute stop at 15 feet would play havoc on my dive computer. Would still have to do a 3 min stop there to keep it from going into error mode.


I didn't think of that.
Can you reprogram an IQ-700?

I'm not sure what the issue here is. On the Pelagic computers, the three minute safety stop is just a recommendation. If you don't do it, the computer doesn't care; it doesn't enter error mode and it has no effect on the nitrogen calculations for the next dive.

On the Seiko based computers (Tusa, Suunto, Cressi) it may matter and it may not. If you have not violated the ascent speeds for the computer, the safety stop is a recommendation, and if you skip it or do it differently, nothing happens. If you have gotten a SLOW warning, then the safety stop is manditory and if you don't do it like the computer says, it affects the nitrogen calculations and you get less time on your next dive.

So, if you have a dive within NDL and don't get an ascent speed warning, you can follow the NAUI recommendation instead of the currently displayed 3 minute at 15 feet recommendation and neither computer should care after you get to the surface.

longtailbda
06-12-2008, 04:23
Just went through a refresher course with Padi there is no change recommendations from them yet.

Sansho
06-12-2008, 05:19
I just looked DANs site over, and didn't see anything about recent changes to decompression stop recommendations.

Vercingetorix
06-12-2008, 06:53
This recommendation has been around awhile. When I did NAUI AOW (Apr 2007), we did a stop at the half-depth for two minutes (I believe) and another at 15 feet for 3.

chinacat46
06-12-2008, 06:57
If I've got the gas which I usually do I'm doing a 3-5 min stop at 15 feet regardless. It can't hurt.

scootermcfly
06-12-2008, 07:03
I know on my Mares M2 a deep stop is recommended by the comp-I think it uses the deepest depth along with how much time you spent there to calculate how deep the first stop is. I believe the M2 is known for having a conservative algorithm.

dive10killer
06-12-2008, 07:11
I have not heard of this. But why not. Just do both stops.

mitsuguy
06-12-2008, 07:14
keep in mind guys that these stops are assuming relatively square dive profiles... almost all of my diving recently requires no real safety stop, it's just a natural progression of how I dive - obviously I do complete safety stops every time but how I do them makes them a lot more fun... for instance...

a dive to 90 feet, pretty common here in the lake, I'll descend down to the platform, usually tie a reel to it, and go exploring around the same depth from there, then come back... swim back along a line, and around 40 feet is where some other cool stuff is, so I'll spend some time around that area, then when done swim back to shore underwater... the shelf angles up, then it's about a 3 minute slow swim to shore from when you get to 20', so, I never really do a safety stop per se, but I spend time at half max depth, and also a good 3 minutes around 15 feet, its just all swimming, and dive planning that allows it...

I agree with NAUI though, it's definitely a good idea, based on proven theory, and it definitely can't hurt... I do agree with everyone else here about still doing the 3 min / 15 ft safety stop, air permitting....

fire diver
06-12-2008, 07:38
...... I never really do a safety stop per se, but I spend time at half max depth, and also a good 3 minutes around 15 feet, its just all swimming, and dive planning that allows it...

I agree with NAUI though, it's definitely a good idea, based on proven theory, and it definitely can't hurt... I do agree with everyone else here about still doing the 3 min / 15 ft safety stop, air permitting....

Thats the beauty of it though, you ARE doing safety stops. For standard rec profiles and light deco, there is no need to just hang motionless in one spot for a stop. Light swimming at the depth is fine, and by some studies it may be better than being motionless, for the elimination of gas loading.

The thing to keep in mind is that the ascent profile should look like a curve when time-based. That is the reason for "stops", to make your ascent match that curve. If you can adjust how fast you come up, (like slowly coming up the incline to shore) you really don't have to ever stop.

Largo
06-12-2008, 08:36
This recommendation has been around awhile. When I did NAUI AOW (Apr 2007), we did a stop at the half-depth for two minutes (I believe) and another at 15 feet for 3.


I don't want to be that guy who is always correcting people, because nobody likes that guy. But I want to clarify.

NAUI's previous recommendation was a 1 minute stop at half the deepest depth reached, plus a 3-5 minute stop at 10-20 feet.

The new recommendation, adopted in March, 2008, is 2-3 minutes at half the depth reached, plus a 1 minute stop at 10-20 feet.

Vercingetorix
06-12-2008, 08:43
I don't want to be that guy who is always correcting people, because nobody likes that guy. But I want to clarify.

NAUI's previous recommendation was a 1 minute stop at half the deepest depth reached, plus a 3-5 minute stop at 10-20 feet.

The new recommendation, adopted in March, 2008, is 2-3 minutes at half the depth reached, plus a 1 minute stop at 10-20 feet.A big THANK YOU for the clarification. It's OK to be That Guy when you can help prevent misunderstandings or have updated info, which you do.

diver-wife
06-12-2008, 10:07
If I've got the gas which I usually do I'm doing a 3-5 min stop at 15 feet regardless. It can't hurt.
very true, you have the air, go slowly, take your time, the slower and longer the better

ianr33
06-12-2008, 10:52
The new recommendation, adopted in March, 2008, is 2-3 minutes at half the depth reached, plus a 1 minute stop at 10-20 feet.

That makes no sense to me at all!

So the suggestion for a dive to 130 feet is 3 minutes at 65 feet and 1 minute at 10 feet?

Stopping briefly at half depth then doing a slow ascent to safety stop depth is a very reasonable thing to do,but doing most of the stops at half depth is insane!

All plans for deco dives have more time at each stop as the stops get shallower

Rainer
06-12-2008, 11:01
All plans for deco dives have more time at each stop as the stops get shallower

These aren't deco dives.

Rainer
06-12-2008, 11:10
GUE's recommendation for NDL/MDL dives is to do "min deco":

Ascent to 50% max depth at 30'/min.
First stop at 50% depth for 1 min.
From there, 1 min stops every 10' to surface (1 min stops = roughly 30 seconds to slide to new depth, 30 seconds at that depth).

Min deco on a dive to 80' would look like:
Just over a minute to get to 40'.
One minute at 40'.
30 seconds to 30', 30 seconds at 30'.
30 seconds to 20', 30 seconds at 20'.
30 seconds to 10', 30 seconds at 10'.
30 seconds to surface.

This is the MINIMUM deco GUE recommends. For dives in the 80-100' range, we'll often double the 30-20-10' stops. It's rather conservative. That's the GUE way.

Really, though, most of the slide-stop stuff is just to gain practice for moving on to technical diving. These are not mandatory decompression stops.

Personally, I have felt better post-dive since I adopted these ascent guidelines for recreational dives. Just generally less tired.

Navy OnStar
06-12-2008, 11:42
Doing my AOW and my PADI instructor started using it.

ianr33
06-12-2008, 13:36
All plans for deco dives have more time at each stop as the stops get shallower

These aren't deco dives.

Every dive is a deco dive :smiley20:

Whether its a deco dive or an NDL dive the shape of deco curve , safety stop curve or whatever you want to call it should be similar.(Less important to get ot right on the NDL dive obviously)

Just dont see the point of doing a 3 minute stop at 60 feet ,1 at 10 and then surfacing.

Rainer
06-12-2008, 13:42
Sorry, meant to say: these dives don't require any mandatory decompression in addition to the dictated ascent rates if you're willing to accept the minimal risk such entails. How's that? Regardless, I agree, not really sure I understand the reasoning behind the new NAUI recommendation. Certainly doesn't jive with dives require just a few minutes of mandatory decompression.

ianr33
06-12-2008, 13:47
Sorry, meant to say: these dives don't require any mandatory decompression in addition to the dictated ascent rates if you're willing to accept the minimal risk such entails. How's that?

I can live with that statement :smiley20:

Foo2
06-12-2008, 14:06
I totally understand the rule of halves. But I'll admit, I'm a little confused as to why they are only recommending 1 min at 15' instead of 3 mins. Does anyone have the answer to that?

Largo
06-12-2008, 14:13
It would be nice if there were a physician who understands diving maladies, on this forum.

Maybe that guy with the inner-ear video would be interested?

diver-wife
06-12-2008, 14:55
I totally understand the rule of halves. But I'll admit, I'm a little confused as to why they are only recommending 1 min at 15' instead of 3 mins. Does anyone have the answer to that?
I agree, especially on deeper dives (deeper than 100ft). 3 min at 50 feet and then 1 minute at 15 feet? I think it would be better to have longer time at 15 feet, as that is where you off-gas more. I personally ascend really really slow, mainly after I hit 50 feet, then spend a min of 3 minutes at 15 feet, then take about another 1 minute or so to go that last 15 feet. I would rather be safer. Then I can even spend some time with my head about water and body in the water (like cave-divers who "surface deco")

Largo
06-12-2008, 17:24
How about a forum area for health / medical stuff?

Maybe it is already there, and I didn't notice it.

Mtrewyn
06-12-2008, 17:39
How about a forum area for health / medical stuff?

Maybe it is already there, and I didn't notice it.


I think this is a Great idea :smiley20: Any Dr.'s that do dive med. or Dive med techs on the forum?

calwolf
01-13-2009, 14:33
I realize that this thread hasn't had a post in a while, but I thought I'd point out that the journal article (Bennett et al. 2007) that started the discussion on deep stops is now publicly available (more than 12 months old), and well worth reading.

Here's a link:

Rubicon Research Repository: Item 123456789/7901 (http://archive****bicon-foundation.org/7901)

And here's the conclusion of the paper:

"We conclude that 2.5 min at 15 msw (50
fsw) is the optimal deep stop time following
25 msw (82 fsw) dives for 20 to 25 min for
preventing PDDB. Shorter or longer times are
not as effective. The shallow stop at 6 msw (20
fsw) for 3-5 mins normally recommended does
not seem as important. However, longer times
do not afford additional benefit in reducing
PDDB."

Flatliner
01-13-2009, 14:57
I realize that this thread hasn't had a post in a while, but I thought I'd point out that the journal article (Bennett et al. 2007) that started the discussion on deep stops is now publicly available (more than 12 months old), and well worth reading.

Here's a link:

Rubicon Research Repository: Item 123456789/7901 (http://archive****bicon-foundation.org/7901)

And here's the conclusion of the paper:

"We conclude that 2.5 min at 15 msw (50
fsw) is the optimal deep stop time following
25 msw (82 fsw) dives for 20 to 25 min for
preventing PDDB. Shorter or longer times are
not as effective. The shallow stop at 6 msw (20
fsw) for 3-5 mins normally recommended does
not seem as important. However, longer times
do not afford additional benefit in reducing
PDDB."

I don't know how many posts I have read over the years that state something like, "I don't think that's a good idea, therefore it's dumb and I'm going to go on doing this..." As we see in the quote above, NAUI based their new recommendation on actual research data. I think we should all be careful being too dogmatic about anything. I have lost count of how many things I was taught as a new nurse that subsequent research has shown was a bad idea regardless of how "logical" it seemed at the time.

Not trying to troll, just offering some food for thought. Thanks for taking the time to dig out the relevant quote Calwolf.