: For nearly 60 hours (about three days), Harrison survived in complete darkness, wearing only his boxers and a singlet.
If you'd like, I can find more from the divers who found him or details on the physics of the air pocket that kept him alive. Harrison - Underwater
: While searching the murky rooms, a diver was startled when a hand reached out from the darkness and grabbed his arm. : For nearly 60 hours (about three days),
: Because Harrison had been at that depth for so long, his body had become "saturated" with pressurized gases. Bringing him to the surface too quickly would have been fatal, so he had to be transferred to a diving bell and then spend another 60 hours in a decompression chamber. Life After the Depths : Because Harrison had been at that depth
: With no food and thinning oxygen, his only sustenance was a single bottle of Coca-Cola he found floating in the wreckage. The Miraculous Rescue
Despite the trauma of being the sole survivor, Harrison eventually faced his fear of the water. In 2015, he became a professional diver himself, trained by the very team that had rescued him from his "underwater tomb".
South African saturation divers were eventually sent to the wreck, but they were tasked with recovering bodies, not finding survivors.