Dear Allison,
Thank you very much for writing to me out here in the Pacific. Alvin has enough oxygen to be able to stay down for about 72 hours but that is only in case of an emergency. On a normal dive, we leave the ship at 8:00 o'clock in the morning and return back on deck at 5:00 PM, so we're inside
the sub for about 9 hours. It takes about 1 1/2 hours to get down to the bottom where we are diving now and about 1 1/2 hours to get back up. This means that we are on the bottom for about 6 hours.