The most important element is their unconventional diving equipment. Rebreathers produce no bubbles and allow the filmmakers to silently stay underwater for up to twelve hours on a single dive. For the first time, underwater cameramen were able to stay down long enough to allow timid sea creatures time to become accustomed to the lights and activity, and so resume their lives and their elusive and exotic underwater behavior. Patience is the second critical ingredient. The nervous male apparently had to go through stages of fear, anger, and outright hostility toward the intruders before finally deciding to ignore them and go about the business of luring a female to his nest.
Luck can often pay off with amazing discoveries.
The chance mention by an assistant of seeing some batrays at the edge of a kelp forest led Mr. Hall to discover and film a stunning and enormous congregation of these graceful gliders circling in an elaborate never-before witnessed mating ritual. In the dark and shadowy world beneath the ocean's surface, danger always lurks for adventurous filmmakers just beyond the small circle of light in which they operate. Crew member Cranston recalls an instance of being suddenly struck by something big and powerful. He never saw what struck him, but discovered his left hand suddenly immobile in a swirl of bloody water. Apparently a large needlefish, blinded by the strong lights, had inadvertently stumbled into him and slashed a hole clean through his arm.