Jacques Piccard was still taking dives into his seventies
Swiss marine explorer and inventor Jacques Piccard, who was part of the deepest submarine dive in history, has died at his home aged 86.
In 1960, Piccard and US co-pilot Don Walsh took a submersible developed by his father to the bottom of the Mariana Trench in the western Pacific.
They went 11km (seven miles) beneath the surface of the sea.
Their discovery of living organisms at that depth led to a ban on the dumping of nuclear waste in ocean trenches.
"By far the most interesting find was the fish that came floating by our porthole," Piccard said afterwards.
"We were astounded to find higher marine life forms down there at all."
'Relishing the unknown'
News of Piccard's death was announced in a message carried by the website of his son, the balloonist Bertrand Piccard.
"One of the last great explorers of the 20th Century, a true Captain Nemo who went deeper than any other man, Jacques Piccard passed away on Saturday... at his home on the edge of his beloved Lake Geneva," it said, referring to the hero created by French writer Jules Verne in his novel Twenty Thousand Leagues Under The Sea.
Bertrand Piccard added:
"He passed on to me a sense of curiosity, a desire to mistrust dogmas and common assumptions, a belief in free will and confidence in the face of the unknown."
Jacques Piccard was born in Brussels, son of balloonist Auguste Piccard. He studied in Switzerland, where he settled.
After the Mariana Trench dive, he worked for the US space agency Nasa, exploring deep seas, and built four mid-depth submarines, including the first tourist submarine which he used to take passengers into the depths of Lake Geneva.