What is the deepest diving expedition recorded?
Bathyscaphe Trieste
The descent to the ocean floor took 4 hours 47 minutes at a descent rate of 0.9 metres per second (3.2km/h; 2.0mph).[6][7] After passing 9,000 metres (30,000ft), one of the outer Plexiglas window panes cracked, shaking the entire vessel.[8] The two men spent barely twenty minutes on the ocean floor. The temperature in the cabin was 7°C (45°F) at the time. While at maximum depth, Piccard and Walsh unexpectedly regained the ability to communicate with the support ship, USS Wandank (ATA-204), using a sonar/hydrophone voice communications system.[9] At a speed of almost 1.6km/s (1mi/s) – about five times the speed of sound in air – it took about seven seconds for a voice message to travel from the craft to the support ship and another seven seconds for answers to return.