Australian Tim Macdonald and New Zealander Rob McCallum this week set a depth record for both nations as they became the deepest diving Australian and Kiwi ever.
The pair achieved a preliminary depth of 10,925 meters (35,843 feet) at the bottom of the Challenger Deep in the Mariana Trench southwest of Guam.

The 12-hour dive was completed in the world’s only submersible certified for operations at any depth in any ocean — the DSV “Limiting Factor,” owned by Caladan Oceanic.
According to McCallum:
“We did spare a thought for Sir Ed [Hillary] as we descended through 8,850 meters [29, 035 feet, the equivalent height of Everest] and still had another couple of kilometers to go. It’s a very long way down and testament to the incredible engineering that has gone into this vehicle and to the team that support it.”
The dive’s primary purpose was to test acoustic navigation equipment that will be used as an aid to deep ocean research. When operating at extreme depths, researchers need to rely on acoustic telemetry to navigate to know precisely where samples were collected.
MacDonald said:
“It was a busy dive but we took the time to set a light-hearted world record; the world’s deepest ever vegemite sandwich, and Anzac biscuits; which is something only Australasian’s really understand.”
The pair conducted a series of technical acoustic tracking exercises, ran a 2000-meter (6562 foot)-long high-definition camera transect and collected geological samples. During the dive, the submersible interacted with three autonomous “landers” that had been placed on the seafloor prior to the dive and used its manipulator to collect geological samples.
