He won a number of athletic titles at the Otago and Southland Inter-Secondary school championships, and ran his first marathon at 17, recording a time of three hours, 10 seconds.
In 1969/70, he spent 13 months in Antarctica as a member of New Zealand's Department of Scientific and Industrial Research Antarctic Expedition where he was in charge of seismology, geomagnetics and earth currents.
McKerrow has climbed and trekked extensively in New Zealand, Europe, Peru, Antarctica, Borneo, East Africa, Nepal, India, Central Asia,[6] and has also been a member expeditions to the Arctic and Antarctic.
In 1985, polar explorer and arctic conservationist Will Steger invited McKerrow to join him on a training expedition in preparation for an unsupported trip with dogs to the North Pole the following year.
[8] In 2011, a 25th anniversary of their North Pole Expedition was held in Minneapolis and at this public event, team members shared their own eyewitness stories on climate change: Canadians Richard Weber and Brent Boddy talked about a loss of thick, old, multi-year ice, shortened dogsledding seasons and the loss of the summer sea ice in the Arctic Ocean; wildlife biologist, Geoff Carroll provided his insight into impacts to Alaska's large land mammals he studies, like caribou and musk ox; McKerrow talked about communities in the Bay of Bengal being squeezed out by rising water levels; and Bob Mantell talked about the impact of the BP oil spill on communities in New Orleans, where he lives.
Bob McKerrow has been involved in 15 earthquake relief-to-recovery operations including Tonga, India, Afghanistan, Nepal, Tajikistan, Uzbekistan, Kyrgyzstan and up until mid 2013, heading the tsunami recovery in Indonesia and Sri Lanka.
McKerrow left the IFRC in August 2013, and in November 2013 took up the position of country coordinator for the Swiss Red Cross after the extremely devastating Super Typhoon Haiyan (or Yolanda as locally known) in the Philippines.
Through this technique, using New Zealander helicopter pilot Colin Tuck, they paved the way for critical supply routes to be opened and provide urgent food and shelter materials.
In July 2010 he took up appointment as head of delegation for IFRC in Sri Lanka with key tasks of drawing tsunami operations to a close, working with Sri Lanka Red Cross Society to implement a large programme in the north and east of the country, providing houses, livelihoods, water and sanitation plus community based first aid and risk reduction projects to people internally displaced by a war that lasted over 25 years.
In July 2012 he led a 'breakthrough initiative' by signing an agreement with the Indian Government to implement the construction of 16,800 owner driven houses for extremely vulnerable people who lost everything in the war.
For two years (1988–89) he ran an experimental youth at risk programme for young people at the Arapaepae Outdoor Pursuits Centre for offenders labelled as 'designed for maximum security prisons.'