Variable Weighted Apnea (VWT) uses a weighted sled for descent. Athletes return to the surface by pulling themselves up a line or swimming. World record holder as of 1 November, 2015 is Stavros Kastrinakis (GRE) at 146m. Professional Association of Diving Instructors (PADI) is the largest and most widely recognised certification and training organisation for divers of all levels. Alternate qualifications exist with BSAC, SSI and a number of lesser known training organisations.
AG Outdoor undertook the PADI OW certification with the incredibly friendly Matt and Kim at Dive Spear and Sport in Mona Vale, Sydney. (www. divespearandsport.com.au). OW packages start at $495 per person, and consist three days on a course of no more than eight people, PADI e-learning, certification, four boat dives, all gear hire, tanks and instructor.