jump to navigation

Introducing “Narco Stops” September 3, 2012

Posted by Chris Sullivan in Technical Diving.
Tags: , , , , , , , , , ,
trackback

Despite the tongue in cheek name this is actually a serious suggestion for divers who go into narcosis territory on air. Generally accepted to begin at 100′, but sometimes experienced (first-hand by me) at shallower depths, narcosis ranges from a pleasant buzz to a creepy feeling of paranoia, and from a mild impairment to unconsciousness. On yesterday’s dive 3 out 4 team members had the creepy kind, while I had the more pleasant form. The first time I had it was on a wreck diving course at about 85′, where I had the “what am I doing here?” feeling as soon as I entered the wreck, even though I knew there were people all around me making sure I was safe. The way I managed it then was to focus on the task at hand, and I still use that along with regular cross checks to keep my mind moving.

Here’s another method of managing narcosis which we tried today, and it worked very well. Today’s dive on the Oconto (more about that later) was a little deeper than yesterday’s. There were 3 of us on the dive, and we had discussed making a slow descent as we’ve noticed that narcosis tends to be worse for a while after a fast descent. On yesterday’s dive the descent from 40′ to 175′ was only two minutes, and we thought that contributed to the heavy narcosis the team experienced at the beginning of the dive. The darkness and low visibility were also contributing factors on both day’s dives.

So we hit on the idea of stopping the descent for 30 seconds about every 50′ and today, no one had narcosis problems on the dive. The brief stop is also useful for bringing team members closer together, doing additional checks, and so on. The result was none of us had any narcosis issues. That’s not to say we weren’t narced – just that it wasn’t a problem on the dive. Our underwater coordination and decision making was good and we started our ascent exactly on time.

Deep air diving isn’t for everyone, but one way of reducing risk due to diver narcosis is to do narco stops on the way down (if PADI or another agency adds them to the curriculum, then they’ll probably call them something like “descent stops” or “staged descents”). You heard it here first.

Advertisements

Comments»

1. Diving the Oconto « Chronicle of an older diver - September 4, 2012

[…] the narco stops plan we came up with the night before, we stopped at that ledge for half a minute or so. At […]

Like

2. Diving the Roy A. Jodrey « Chronicle of an older diver - September 6, 2012

[…] a sort of a bowl at around 30′ before turning into a steep wall. As with the day before, we stopped at various intervals on the descent to rest, regroup and keep our heads clear.  There was a mild upward current as we […]

Like

3. Changing Attitudes to Deep Air « Chronicle of an older diver - September 13, 2012

[…] between what is reasonable and what is not. Perhaps I’m already past it. I think that the narco stop concept has reduced some of the risks, but I still know that my reactions are slowed by the onset […]

Like


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: