Dreyer's father, Theo and mother, Marie, raised him in the town of Vereeniging, about 35 miles south of Johannesburg. Dreyer designed "obscenely loud car stereos", had a passion for diving, and loved adventure,. Outside Magazines Tim Zimmerman reports:
Deon had logged about 200 dives when he was invited to join some South Africa Cave Diving Association divers at Bushman's Hole over the 1994 Christmas break. They planned a descent to 492 feet and asked Deon to dive support. He was thrilled. Two weeks before the expedition, Deon's grandfather passed away. Sitting around a barbecue with his family one night, Deon spoke with boyish hubris. "He said if he had a choice of how to go out in life, he'd like to go out diving," recalls his father, Theo, 51.
Death
Dreyer drowned on 17 December 1994, aged 20, during a practice dive while helping a team, assembled by Nuno Gomes, set up conditions for a deep, technical dive scheduled to take place later that week. According to first-hand accounts from those diving with him, Dreyer was lost on ascent around from the surface. They conjectured he had probably lost consciousness either because of oxygen toxicity or hypercapnia induced by the high work-rate of breathing at depth. Two weeks after Dreyer's death, Theo hired a small, remotely operated sub used by the De Beersmining company. It found Dreyer's dive helmet on the cenote floor, but there was no sign of his body.
Commemoration
Dreyer's parents erected a plaque on a rock wall above the Bushman's Hole entry pool, in memory of their son. In Phillip Finch's book Diving Into Darkness: A True Story of Death and Survival, it was suggested that one of the reasons Dreyer's death created such an impression on the cave diving community was because of the plaque. The bodies of most other divers who die, even whilst cave diving, are recovered. However, for many years it was assumed Dreyer's body would never be recovered from the cave because it was simply too deep, but the plaque was a continual reminder to cave divers that his body lay within.
Recovery of body
Ten years later, in October 2004, renowned cave diver David Shaw discovered Dreyer's body in the cave at a depth of. On 8 January 2005, Shaw tried to recover the body, but died in the attempt. Shaw's close friend and support diver, Don Shirley, also nearly died and was left with permanent damage that has impaired his balance. On 12 January 2005, while others were recovering Shaw's technical equipment, they discovered the bodies of both Dreyer and Shaw had floated up close to the surface. Both bodies were then recovered.
