In 1943, French underwater explorer Jacques Cousteau helped create an invention designed for underwater breathing, and 60's British rock group Jethro Tull named an album after it. What is it?

In 1943, a groundbreaking invention emerged from the collaborative efforts of French explorer Jacques Cousteau and engineer Émile Gagnan. This revolutionary device allowed divers unprecedented freedom beneath the waves, moving beyond cumbersome surface-supplied air hoses. It was the first commercially successful open-circuit self-contained underwater breathing apparatus, or SCUBA system, and it was famously known as the Aqualung.

The Aqualung transformed humanity's relationship with the ocean. Prior to its development, underwater exploration was largely limited to heavy, restrictive diving suits. Cousteau's invention, however, opened up the vibrant marine world to widespread scientific study, filmmaking, and recreational enjoyment. His subsequent expeditions aboard the Calypso and his popular documentaries further showcased the wonders of the deep, inspiring generations to explore and protect the underwater environment.

Decades later, the name of this iconic diving apparatus found an unexpected second life in the world of rock music. In 1971, the British progressive rock band Jethro Tull released their critically acclaimed album, also titled Aqualung. While the album’s lyrics often explored themes of societal outcasts, poverty, and religion, the titular character and the album's name itself became synonymous with the band's distinctive sound and enduring legacy, linking the pioneers of undersea exploration with the pioneers of rock.