Incredibly there have been more astronauts on the moon, than divers who have conducted dives more than 5500 meters above sea level. Each dive at these altitudes is an experiment and trial in how the human body can react to increasing water pressures when set in the context of extremely low atmospheric pressure.

The Nevado Tres Cruces MedExpedition 2015 explored Tres Cruces Norte Lake. This lake is situated in the crater of an extinct volcano 5907 meters above sea level, one of the highest volcanoes in the world. Situated on the brink of the driest region in the world, the Atacama Desert on the border of Chile and Argentina.

The dive took 23 minutes and achieved a maximum depth in the lake of 11 meters. Even at 11m the challenges of accounting for the low atmospheric pressure at high altitude, including altitude sickness. Logistical issues caused by the need to transport cylinders and diving equipment to nearly 6000m up a mountain with the associated fatigue caused by climbing. Additional physiological and psychological effects such as deteriorated mood was also experienced.

The preparation and planning for this expedition took over six months and gear choice was key. Not just for diving safety, but to be transportable and robust enough to survive the journey to the dive site. Sidemount offered a flexibility in this regard that proved to be a significant part of the expedition’s success.