Are very slow final ascents better?

[BigTuna]

If deeper than 40 ft add a one minute stop at half of your deepest depth and then do a 3-5 minute precautionary stop at 15-20 fsw. If you are diving a computer, you should do a FIVE minute safety stop.

Is that the current NAUI practice or is it simply what you do? (I'm a PADI guy...)

 

[vapovick]

slower the better, if you planned your dive right, you should have the gas to stay for a while and take it slow, whats the rush?

Plus the people below you doing their stop send up a jucuzzi of bubbles....

 

[The Chairman]

It's current NAUI STANDARDS to be taught.

 

[BigTuna]

Research has been done by IDAN and they have been working with an Italian research team as well as NAUI who has been doing research in deco for technical diving.

Somebody on another thread gave me links to the paper you're describing, and I've been poring over it. This ascent would be consistent with the best profiles reported in the paper: 30 fpm ascent rate, 5 min deep stop, and 5 min safety stop. The total ascent time needs to be comparable to that of neurological tissue's half time, or about 12 min. This ascent is "best" in the sense that it allows fast tissue to off-gas without significant bubbling.

- How deep should the deep stop be? The paper doesn't specify this, having selected a specific deep stop depth for a specific dive depth. A good choice seems to me to be 1/2 the dive's maximum depth. This would seem to put it somewhat above the depth at which off-gassing starts. Has NAUI adopted this definition?

- How long should the deep stop be? The paper's profiles used a 5 min deep stop (plus a 5 min safety). Reading between the lines, it seems like NAUI might be recommending only a 1 min deep stop, with the minute "borrowed" from the conventional safety. This seems like only a token nod to the Marrioni results and doesn't ensure an ascent duration comparable to neurological tissue's half time. Can somebody explain what's going on?

 

[BigTuna]

It's current NAUI STANDARDS to be taught.

So, if I'm getting it, NAUI embellishes a "conventional" ascent by adding a 1 min stop at 1/2 max depth, AND they extend the safety stop for computer users (since there's no table rounding protection for them). That right? Do they make a special recommendation for the ascent rate from the safety stop?

 

[The Chairman]

It's been at least a year since we got the new standards for the safety stops. I have seen no additional recommendations on surfacing speed. They stick to the conventional 30fsw/minute probably for simplicity's sake.

 

[BigTuna]

It's been at least a year since we got the new standards for the safety stops. I have seen no additional recommendations on surfacing speed. They stick to the conventional 30fsw/minute probably for simplicity's sake.

Thanks, Pete.

 

[BigTuna]

Right now I'm having amnesia and deja vu at the same time. I think I've forgotten this before........

Me, too! I almost forgot that you were a blonde a few hours ago. Or was that in an alternate universe....

Hey! Not fair. You're not even a girl!

 

[Fish_Whisperer]

Try it, you'll even feel better........if you are feeling tired after diving, you are ascending too fast.

Wow! No kidding... Thank you very much for this bit of advice.

Plus, really slow ascents just feel really cool...

 

[limeyx]

yes... basically, any time spent above 33 feet is good, giving your body a chance
to offgas at leisure

what i do is a 3 minute stop at half my max depth, then slowly to 30 feet,
then do a minute there, then REALLY SLOWLY to 20 feet, and spend as much
time as i feel like it there, then REALLY SLOWLY to 10 feet and again spend
as much time as i feel like there, and then REALLY SLOWLY ascend to surface

keep an eye on your computer. you will see that your "max time" continues to increase. this means that you are not incurring any additional nitrogen loading.
quite the contrary, you are reducing your surface interval.



i think this is cheating, but it's what i do. i will go up two feet and stop,
then wait five seconds, then go up two feet and wait five seconds, and
so on.... it's start, stop, start, stop all the way up.

i guess it's cheating, but it works for me!

I dont think it's cheating. One thing I will do (if I know I am have not drifted too far from boat) is a 6 minute ascent from 20.

Basically, hang at 20 for 1 min, then ascend to 17, then when the next minute clicks over, go to 14 etc. ending up at 5 feet. Great buoyancy practice and really slows the ascent down.