Being swept along on this technical diving thing, has been a long, somewhat twisted, but definitely entertaining journey. If you and I had met when the whole affair started, we could not possibly have envisioned how directly and pervasively, what were then radical activities, like cave diving, trimix diving and rebreather diving, would influence the mainstream dive community.
The Royal Mail Ship, Empress of Ireland, was an ocean-going luxury liner on her way to Liverpool from Quebec City when she sank in the Saint Lawrence River, 14 minutes after colliding with a Norwegian collier in the early morning fog of 29 May 1914. She had 1,477 people on board—passengers and crew—and the accident claimed the lives of 1,012, more than 800 of them passengers.
From the Basic Nitrox levels through to advanced Trimix, we base our calculations of dive profiles on a specific partial pressure of oxygen—pO2.
Managing and controlling the pO2 lies at the foundation of any level of technical diving as it enables us to perform longer, deeper and safer dives compared to diving air. But there are also a few points to watch.
A long time ago, I sat in hoosha (Bedouin tent) after a deep air dive in the Blue Hole (Dahab, South Sinai, Red Sea). My good friend and dive buddy had less than an hour ago peeled me of the wall near the bottom of the Blue Hole. I had succumbed to deep water blackout, caused by a high degree of stupidity, wrong kit and inadequate training.