Читать книгу Deeper into the Darkness онлайн
118 страница из 184
Our dates were now set in stone – and with all the acceptances now in from our team, we now had major commitments being made. Paul Haynes, in his capacity of dive safety officer, created a thorough 40-page Dive Brief, and this was emailed out to all the team members six months before the exped. This covered the basics of our planned diving methodology, such as the standardisation of rebreather trimix diluent gas of 15/50 across the team. This provided an oxygen partial pressure (PO2) of 1.2 bar at the deepest depth anticipated of 70 metres, and facilitated an effective rebreather diluent flush without the safety implications of using a ‘lean’ hypoxic gas, where a diver could black out. At the maximum depth of 70 metres, this trimix mixture would give divers an equivalent narcotic depth (END) of 25 metres. This means that at 70 metres the divers would only be experiencing the same nitrogen narcosis as a diver diving on air at 25 metres, next to negligible.
Each diver had to carry sufficient open-circuit bailout gas to independently support a full open-circuit decompression profile in the event of a catastrophic failure of the primary life support rebreather. As a minimum, divers were required to carry an 11-litre cylinder of bailout 15/50 bottom gas under their left arm and an 11-litre cylinder of EAN 60 deco gas on their right side.