Fire fighters who participate in dive training risk lung damage, illness, or drowning. NIOSH investigated fatalities that have occurred during these training exercises and developed recommendations to decrease these risks. Fire fighters may be called on to perform public safety diving actions, including search and rescue and recovery missions. Fire departments and fire fighters preparing for underwater operations must be aware that dive training can be hazardous. Diving hazards include entanglement, running out of air, lung overexpansion injury, panic attacks, and decompression sickness. Entanglement in rope or aquatic plants is an extremely serious hazard that can prevent divers from returning to the surface [Hendrick et al. 2000]. Lung overexpansion most commonly occurs when divers panic and make rapid ascent holding their breath. No sensation of discomfort provides a warning when overexpansion is about to occur [NAUI 2000]. New divers may hold their breath when first learning to use SCUBA equipment [PADI 1990]. Lung overexpansion can result in pulmonary barotraumas causing serious damage to the lungs, including collapse [Bookspan 1995], even when ascending from relatively shallow depths and on relatively short dives. Panic attacks while diving may be provoked by situations such as entanglement, running out of air, or reasons unknown. Panic attacks occur among both veteran and novice divers. Adequate attention to panic and anxiety attacks should be given during diver training. More than half of experienced divers surveyed report having panic episodes while SCUBA diving [Morgan 1995]. Decompression sickness ("the bends") occurs after extended periods of time at depth followed by ascending too quickly, thus preventing nitrogen gas accumulated in the diver's tissues from dissipating properly. Symptoms of decompression sickness can range from skin rash, extreme fatigue, coughing, and painful joints to paralysis and unconsciousness [NAUI 2000].