Early scuba divers dived without a buoyancy aid. Sonar can be used to detect frogmen and other scuba divers. Snorkelers normally wear the same kind of mask as those worn by scuba divers. Scuba and surface-supplied underwater divers and submariners also rely on artificially delivered . Apra Harbor is home to shipwrecks that are popular with scuba divers. It is popular with divers, snorkelers and swimmers. It is becoming a destination for scuba divers and hikers. Reports of recreational scuba divers being attacked by Humboldt squid have been confirmed. They were soon joined by helicopters, watercraft, police divers, and two naval diving teams. Semel was inspired for some of the movements by scuba divers. SPECTRE scuba divers, commanded by Largo, retrieve the atomic bombs. DCS affects approximately 1,000 U.S. scuba divers per year. They object to the activities of American divers who attempt to explore these wrecks. Players can either be divers or sharks. He is also the divemaster of Bikini Atoll Divers.