Episode 4: "SILENT WARRIORS" THE ELITE NAVY DIVERS: Sydney & Shoalwater Bay (Australia) Struggling through miles of knee deep mud, abseiling down sheer precipices, being awakened at midnight and ordered to swim four miles in near freezing waters, disarming underwater explosive devices in little or no visibility. These are just a few of the tasks any young man must endure if he wants to become a member of the navy's elite corps of clearance divers. Andrew and Liz Wight document the progress of 14 Royal Australian Navy recruits subjected to a grueling regime that only the toughest are capable of withstanding.