Don Walsh was the first to go to the very bottom of the deepest part of the ocean in 1960 in a specially designed submarine. The water pressure was 800 tonnes per square inch. Show more
Discover 11,128,835 listings and 277,953 playable programmes from the BBC
Don Walsh was the first to go to the very bottom of the deepest part of the ocean in 1960 in a specially designed submarine. The water pressure was 800 tonnes per square inch. Show more
The BBC's international radio station
