title: Dive problems and risk factors for diving morbidity.
abstract: BACKGROUND
  Running out of air, buoyancy problems and rapid ascents are known risk factors for diving morbidity and mortality. The effects of the diving environment and equipment and the influence of individual diver characteristics on these risks were studied.
  
  
  METHODS
  Between 1995 and 2004, Project Dive Exploration prospectively recorded 52,582 recreational dives made by 5,046 adult divers. Data regarding diver characteristics, dive environment, recorded depth-time profiles and reported dive problems were collected. Ascent rates were calculated from depth-time profiles. Human factors (age, sex, certification status) were tested by logistic regression for association with running out of air, buoyancy problems and rapid ascents. To control for human factors, dives where a problem was reported (case dives) were compared to dives made by the same divers in which each risk factor was not reported (control dives), again using a logistic regression model.
  
  
  RESULTS
  Running out of air and buoyancy problems were significantly associated with older females, whereas rapid ascents were associated with younger males. Certification status also affected which type of problem was experienced. Maximum depth and dive time had only weak effects upon the type of problem experienced. All three problems were associated with charter boat and live-aboard diving, the most significant environmental association being the perceived workload of the dive.
  
  
  CONCLUSIONS
  We recommend dive instructors give greater emphasis during training to monitoring gas reserves, buoyancy control techniques and slow ascents, coupled with practical methods of gauging ascent rate. Dive boat crews should consider likely workloads when selecting dive sites and warn divers against overexertion.
authors: Doctoral student at the School of Population Health, the University of Western Australia.
authors: Peter
authors: P
authors: Buzzacott
authors: Petar J
authors: PJ
authors: Denoble
authors: Olivier
authors: O
authors: Simon
authors: Richard
authors: R
authors: Dunford
authors: Richard D
authors: RD
authors: Vann