Dive Dry with Dr. Bill

#292: Narc'ed? Gee, I Hope Not!

During my high school daze in Chicago, I took German because it was the language for scientists to learn. Besides, my paternal grandparents still spoke it as did my relatives living in the small German community of HüddesdorfbeimStolzenauüberWeser (the name is almost bigger than the village). One of the songs we had to memorize for Herr Bueltmann's class was "Die Lorelei," a beautiful song based on lyrics by the German poet Heinrich Heine. I still sing it in the original German when taking my post-dive shower. Fortunately for them, my neighbors must be a bit hard of hearing.

The song starts off with "Ich weiß nicht, was soll es bedeuten, Daß ich so traurig bin, Ein Märchen aus uralten Zeiten, Das kommt mir nicht aus dem Sinn." It goes on to tell about the beautiful Lorelei who sits on a rock outcropping above the Rhein River and sings beautiful songs to lure sailors and their boats into certain death on the reefs. "Die schönste Jungfrau sitzet Dort oben wunderbar, Ihr gold'nes Geschmeide blitzet, Sie kämmt ihr goldenes Haar, Sie kämmt es mit goldenem Kamme, Und singt ein Lied dabei; Das hat eine wundersame, Gewaltige Melodei."

Before you think Dr. Bill has lost all his marbles (I still have a few left, but no cat's eyes), I should explain what this has to do with diving and marine life. Nothing. Ha, just teasing. It is said that divers experiencing nitrogen narcosis at depth often see strange things such as mermaids. Recently I was doing a deep dive and thought I finally had such a vision, as you can see from the image I took accompanying this column. It was a woman of such beauty that I would have followed her anywhere. The funny thing is she looked a lot like my favorite Chinese actress, Gong Li. I guess I've been watching too many of her movies recently. She truly is a woman to dive for!

Okay, okay... I'll get serious and back on topic. After all, nitrogen narcosis can be a very important issue for divers. Jacques Yves Cousteau referred to it as "rapture of the deep," but what is it? The actual mechanism through which it operates on a diver's nervous system is not known. Some believe it results when the increased partial pressure of nitrogen at depth causes the gas to enter through nerve cell membranes and affect the transmission of nerve impulses. Some have equated it to DUI, "diving under the influence."

The deeper one goes, the greater the chance of significant narcosis. Fortunately its effects are reversible if recognized in time, and the diver ascends to a shallower depth where they usually disappear. Although nitrogen can be toxic if it reaches high enough levels, the effect most frequently encountered is a clouding of one's judgment. This can lead to poor decision making, a loss of focus and bad coordination. More serious cases may make the diver feel more capable than they are, causing them to ignore safe diving practices. Serious exhaustion may result which may prevent the diver from effecting a recovery, especially if they panic under the influence.

While all divers are affected by narcosis to a degree, the severity of the impairment differs between divers, as well as on a day-to-day basis in the same diver. This makes it difficult to establish firm standards. The maximum depth for recreational divers of 130 feet (approximately 40 meters) was set in part due to concerns about narcosis. Throughout the early decades of my diving career, I rarely descended to depths of 100 feet so narcosis was not much of an issue for me. It wasn't until the last few years that I began diving below the recreational depth limit, and felt I needed to assess my response to narcosis.

I've mentioned previously that two things initiated my interest in deep diving. The first was when Bob Kennedy of Scuba Luv brought up some invertebrates from a depth of 250 feet that he asked me to identify. They were brachiopods, a group almost never seen at recreational limits in our waters. I wanted to film them. The second trigger was when one of my occasional dive buddies emerged from a dive with a ghostly white face. He walked over to me holding his computer up for me to see. His maximum depth read 197 feet. He said he was very seriously narced down there as he tried to free the anchor from some old quarry equipment at that depth.

I decided I wanted to experiment to determine my susceptibility to narcosis, and to try to reach depths where I could film brachiopods. Slowly over a period of about two months, I gradually increased my maximum dive depth in roughly 10 foot intervals. I assessed my degree of narcosis by determining whether I could locate subjects to film at depth, frame them properly and follow them if they moved. What I discovered through this "scientific" experiment was that narcosis was present, but did not seriously impair my functioning. I didn't get much goofier than I am at the surface. And I finally filmed plenty of brachiopods and other elements of the "deep ecology" off our island.

It has been said that frequent divers may build up some resistance to narcosis due to elevated levels of nitrogen in their body. I don't believe this has ever been scientifically tested, so I don't know how true it is. I do know that I've done a number of dives in the 180-200 ft range and filmed some of the interesting things (well, to a scientist anyway) I've seen down there. However, when my second HP120 SCUBA tank failed inspection, I stopped diving to these depths. The tank I currently use has a lower air capacity... not enough for me to feel comfortable diving truly deep. And I don't recommend that other divers undertake such dives. For most it is simply a dark and dreary world down there unless worms and sea pens and other critters intrigue you.

What if narcosis had taken over my judgment at depth? Would I continue to follow the beautiful Gong Li... er, mermaid... deeper and deeper to my death? Of course not! I possess the highly disciplined mind of a scientist, and would not be taken in by that lovely illusion and its Lorelei-like charms. Besides, as far as I know she's not a diver so I'm highly unlikely to meet this dream woman down under (except maybe in Australia)! However, were I to see her here on the island... or in China when I finally get over there to dive... I'm sure I'd follow her anywhere! No mind altering narcosis needed in that case. Sigh.

© 2008 Dr. Bill Bushing. Watch the "Dive Dry with Dr. Bill" underwater videos on Catalina Cable TV channel 49, 10:00 AM and 5:00 PM weekdays and on Charter Communications Cable channel 33 at 7:30 PM on Tuesdays in the Riverside/Norco area. Please help me climb out of self-imposed poverty... buy my "Munching and Mating in the Macrocystis," "Great White Sharks of Guadalupe," "Calimari Concupiscence: Mating Squid, " "Playful Pinnipeds: California Sea Lions," "Belize It or Not: Western Caribbean Invertebrates, Fish and Turtles," "Gentle Giants: Giant Sea Bass," "Common Fish and Invertebrates of the Sea of Cortez" or the new "Sharks and Rays of Southern California" DVD's. Yes, take Dr. Bill home with you... we'll both be glad you did!

"Rapture of the deep" in the form of the beautiful Gong Li in a local giant kelp forest.
Dream on, Dr. Bill! OR I'd follow you almost anywhere... but not below 200 feet!

This document maintained by Dr. Bill Bushing.
Material and images © 2008 Star Thrower Educational Multimedia