Nitrogen Narcosis: The Martini Effect
Nitrogen narcosis or inert gas narcosis is a condition that many divers are at risk of when performing deeper dives. Often it begins at around 30 meters (10 feet) of water. In the US, divers refer to nitrogen narcosis as “the martini effect” or “Martini’s Law” as the effect is comparable to drinking a glass of dry martini on an empty stomach for every 10 meter/33 feet descent beyond the first 20 meters/66 feet. The symptoms of nitrogen narcosis include:
Other symptoms may include blindness, debilitating inertia, unconsciousness and death.
Nitrogen narcosis theoretically affects all divers going below 20 meters/66 feet although the intensity may vary from diver to diver and even from dive to dive. For reasons not completely understood. Developing an actual tolerance to nitrogen narcosis is not possible, but with experience, divers can learn to manage and cope with the effects.
The primary cause of inert gas narcosis is nitrogen gas, but it has been discovered that some breathable gases which affect the body tissues, particularly lipid or fatty tissues are also responsible for it. The effects of narcosis are felt mostly in the brain primarily because it is composed predominantly of lipid tissues. The effects intensify as depth increasing with most divers beginning to notice the symptoms at around 30 meters/ 100 feet, and they become severe at around 40 meters/ 140 feet.
The remedy for nitrogen narcosis is descending to a shallower depth, after which the symptoms will dissipate, leaving no known long-term effects. Often, the dive can be resumed at a new, shallower depth. However, a diver may not be able to make the decision to switch depths due to the feeling of euphoria, and this is why diving in a buddy system is important. Once the diving partner notices these effects, he should urge his partner to decrease depth or guide them to shallower waters.
Nitrogen narcosis is a potentially dangerous condition but luckily, easy to manage. Newbie divers should ensure their first dives are with experienced buddies or instructor. Also, they should make sure they have someone to assist them in the case of “the martini effect” until you’ve learnt to cope alone. And of course, newbie or pro, always observe maximum recreational depths.