The boat-deck word for the narcotic effect of nitrogen under pressure. It usually sets in from 25 to 30 metres and feels like two or three beers too many.
Divers say someone \"got narced\" and nobody ever explains it. What they mean is the narcotic effect of nitrogen under pressure: tingling, slowed reactions, a sense of invincibility, sometimes tunnel vision or anxiety. The dangerous part is not the feeling but the judgement behind it — a diver who feels invincible at thirty-five metres stops checking the gauge. The remedy is unusually simple: ascend a few metres together. The partial pressure drops, and symptoms usually disappear within seconds, leaving nothing behind. Two things get underrated. Susceptibility swings from day to day with cold, exertion, stress and medication, so \"I was fine at thirty-five last time\" proves nothing. And pride: hiding symptoms is what turns a harmless effect into the start of an accident chain. Test each other with simple tasks in hand signals.