Ian Vickery has vivid memories of his first helicopter flight. It was the morning of 8 January 1979, and he and his father, Ian Vickery Sr, had lifted off from an airfield in the far south of the Republic of Ireland in a four-seater “bubble canopy” copter.

But this was no joyride. Ireland had just suffered its worst modern maritime disaster: several hours earlier, the Total-owned VLCC Betelgeuse had exploded at the Gulf Oil terminal on Whiddy Island in the Bay of Bantry, killing 50 people.