Billabong Challenge: The Mystery Left: Most professional surfing contests hold their final at a charity beach on a Sunday afternoon regardless of wave quality. The Billabong Challenge, a bold new direction in competition surfing, enticed 8 hot surfers from around the globe to battle a dangerous shark infested reef, at a secret location on the remote desert coast of Outback Australia. Held over a 14 day period, enduring harsh elements, till time and tide set perfect conditions for the ultimate challenge.