Was involved with the nonprofit marine conservation organizations Sea Shepherd Conservation Society, but eventually disassociated himself from the organization and founded his own, Earthrace Conservation
Attended the University of Waikato, where he studied science, and the University of Auckland, where he studied engineering
Co-founded CamSensor Technologies, which manufactured automated camera systems for controlling robots used in complex tasks
Started his career working in the North Sea and Libya as an oil exploration engineer
While pursuing a Master of Business Administration degree from Macquarie University, he wrote a 20,000-word paper about the use of renewable energy for road transport
A conservationist and promoter of bio-fuels, he is known for breaking the record for circumnavigation by powerboat by using only sustainable bio-fuels
Has appeared in a number of television programs pertaining to marine conservation
Bethune and two of his crewmates underwent liposuction in order to convert their own body fat into fuel as a publicity stunt during his circumnavigation
Captained the Ady Gil, previously the Earthrace, until it sank following a collision with a Japanese whaling vessel
Declined a $4 million sponsorship from a company that would have required him to use regular diesel instead of sustainable bio-fuels to fuel his circumnavigation attempts