[citation needed] In 1977, while at Harrow, he inaugurated the school tradition of Long Ducker, a 20-mile run from Harrow-on-the-Hill to Marble Arch and back raising £101.58 for the Queen's Silver Jubilee Fund in the process.
The running of Long Ducker has since become one of the school's major annual events involving pupils, teachers, support staff and parents and can raise in excess of £100,000 for charity each year.
[citation needed] Hadow worked at Mark McCormack's Sports Organisation from 1985 to 1988, acting as an agent representing the European equestrian interests of International Management Group (IMG).
In 2003, Hadow trekked 770 km from Ward Hunt Island, Canada to the North Geographic Pole in 64 days becoming the first person to complete the journey solo and without resupply.
[9] The Survey's observations, viewed in the context of decades of existing measurements by submarines, satellites and buoys, led Professor Peter Wadhams of the Polar Ocean Physics Group (University of Cambridge) to suggest the Survey's work added further evidence to an emerging view that there is a significant probability that by 2020 only 20% of the Arctic Ocean basin will have sea ice cover in the late summer.
[14] In 2010 and 2011 the Surveys, delivered by newly formed Geo Mission Ltd, involved two inter-linked field research components: a seasonal (winter/spring) research base located on the sea ice of the Gustav Adolph Sea on the edge of the Arctic Ocean (off Ellef Ringnes island) amongst Canada's northernmost Queen Elizabeth islands, and a 300 – 450 km transect of the Arctic Ocean surveyed by a team of explorers in the Winter / Spring.
In summer 2017, he led Arctic Mission, which became the first boat expedition without icebreakers to sail into the ice-free international waters surrounding the North Geographic Pole.