Their mission was to “bear witness” to US underground nuclear testing at Amchitka, a tiny island off the West Coast of Alaska, which is one of the world’s most earthquake-prone regions.

Amchitka was the last refuge for 3000 endangered sea otters, and home to bald eagles, peregrine falcons and other wildlife.

Even though their old boat, the Phyllis Cormack, was intercepted before it got to Amchitka, the journey sparked a flurry of public interest.

The US still detonated the bomb, but the voice of reason had been heard. Nuclear testing on Amchitka ended that same year, and the island was later declared a bird sanctuary.

Today, Greenpeace is an international organisation that prioritises global environmental campaigns.

Based in Amsterdam, the Netherlands, Greenpeace has 2.8 million supporters worldwide, and national as well as regional offices in 41 countries.