Give Nitrogen the One, Two, Three Knock-Out Punch

by Dale Sheckler

California Diving News publisher Dale Sheckler has been diving for over 37 years. With thousands of dives under his belt his deepest dive was 400 feet. Suffering from decompression sickness (DCS) twice, Dale passes on to you some of the ways he has learned to finally tame the nitrogen beast with a one, two, three knock out punch.

Dramatically reducing your risk of decompression sickness could be simple as one, two, three... Read More

Dale, I have yet to miss an issue since you started CDN. Keep up the GREAT work in keeping us divers informed.
Friend from long ago.

Good advice, Dale, as always. During my period of deep air diving (180-200 ft), I found that my tolerance to nitrogen narcosis increased markedly over the several year period I was doing it. Back then I was doing as many as 350 dives a year, which I believe was also an important factor as I believe my body acclimated to higher than usual nitrogen levels.

Prior to this period I rarely dove deeper than 100 ft (dating back into the early 60s). On occasion at those max depths I could recognize that I was narc'ed but never to any serious degree. As I gradually increased my depths in preparation for hitting the 200 ft basement depth that I won't exceed on air, I noticed that my mind remained "clear" (well, considering it was MY mind and not a normal one).

By the time I had increased my max depth to 200 ft, I had no significant problem with narcosis. As a scientist, I assessed this (subjectively of course) by my ability to locate, frame and follow the subjects I was diving to such depths to film.

When I ended these deep dives about three years ago, and my frequency of diving decreased (in the range of 50 dives this year... sigh), my tolerance for narcosis greatly diminished. I was noticeably narced as shallow as 107 ft on one dive and narced beyond anything I'd ever experienced when I dove the Infidel (155 ft).

As for potential DCS, during those deep dives (and today on shallower ones) I always utilized several deep stops as well as extending my required deco, usually by a factor of two and sometimes three. Of course here off Catalina that is easy since the bottom topography has a steep slope that allowed me multiple opportunities to stop along the way to film something... and extended periods in the shallows (above 30 ft) to off gas. So far in almost 50 years of diving I've never taken a hit (keeping fingers crossed and safety stops frequent and as long as possible).

By the way, "best fishes" to you and your family for the holidays!

Mark Guccione:

Dale, I have yet to miss an issue since you started CDN. Keep up the GREAT work in keeping us divers informed.
Friend from long ago.

Click to expand...

Thanks for all the support through the years!