Driven by an unquenchable thirst for discovery, he was repeatedly drawn to the rims of volcanoes. Accompanying him into the heat of eruptions was his Explorer  II, which he wore over the sleeve of his thermal suit.

In a letter addressed to Rolex in 1972, he wrote: “[My watch] has just passed, with flying colours, its first – and extremely demanding – volcanic test, in very aggressive gases on Mount Etna. It worked perfectly, which was not the case for the watches of my teammates.”