diver's training, experience or physical capacity. Decompression sickness and arterial gas embolism in recreational diving have been associated with specific demographic, environmental, and diving behavioural factors. A statistical study published in 2005 tested potential risk factors: age, asthma, body mass index, gender, smoking, cardiovascular disease, diabetes, previous decompression illness, years since certification, number of dives in the previous year, number of consecutive diving days, number of dives in a repetitive series, depth of the previous dive, use of nitrox as breathing gas, and use of a dry suit. No significant associations with risk of decompression sickness or arterial gas embolism were found for asthma, body mass index, cardiovascular disease, diabetes or smoking. Greater dive depth, previous decompression illness, number of consecutive days diving, and male biological gender were associated with higher risk for decompression sickness and arterial gas embolism. The use of dry suits and nitrox breathing gas, greater frequency of diving in the previous year, greater age, and more years since certification were associated with lower risk, possibly as indicators of more extensive training and experience. Risk management has three major aspects besides equipment and training: Risk assessment, emergency planning and insurance cover. The risk assessment for a dive is primarily a planning activity, and may range in formality from a part of the pre-dive buddy check for recreational divers, to a safety file with professional risk assessment and detailed emergency plans for professional diving projects. Some form of pre-dive briefing is customary with organised recreational dives, and this generally includes a recitation by the divemaster of the known and predicted hazards, the risk associated with the significant ones, and the procedures to be followed in case of the reasonably foreseeable emergencies associated with them. Insurance cover for diving accidents may not be included in standard policies. There are a few organisations that focus specifically on diver safety and insurance cover, such as the international Divers Alert Network Training and certification Scuba training is normally provided by a qualified instructor who is a member of one or more diver certification agencies or is registered with a government agency. Basic diver training entails the learning of skills required for the safe conduct of activities in an underwater environment, and includes procedures and skills for the use of diving equipment, safety, emergency self-help and rescue procedures, dive planning, and use of dive tables or a personal dive computer. Scuba skills which