25 to 29 years, 30 to 34 years, 35 to 39 years, 45 to 49 years, caucasian, classmate, concentration, diver, diving, education, explaining, guidance, helmet, holding, indoors, instructor, learning, life jacket, listening, low angle view, man, mature adult, mature man, mentoring, mid adult man, mid adult, offshore oil worker, male, protection, safety equipment, safety, scuba diving, serious, shirt and tie, showing, standing, student, survival skill, survival training, swimming pool, talking, teacher, teaching, together, training facility, training, watching, wearing, wet suit, young adult