Limiting the risk of equipment malfunctions that could cause a loss of breathing gas.Efficient use of the available gas during the planned dive and during an emergency.Awareness of the critical pressures and using them to manage the dive.Monitoring the contents of the cylinders during a dive.variation in consumption due to dive conditions and personal physical and mental condition.variation in consumption due to depth variation.basic consumption at the surface for variations in workload.Knowledge of personal and team members' gas consumption rates under varying conditions.Gas planning is one of the stages of scuba gas management. Specifying the critical pressures of relevant gas mixtures for appropriate stages (waypoints) of the planned dive profile (gas matching).Calculation of the pressures for each of the gases in each of the cylinders to provide the required quantities.Each cylinder volume and working pressure must be sufficient to contain the required quantity of gas. Choice of cylinders to carry the required gases.
Both of these lead to a higher gas consumption during an emergency exit or ascent. Under stress it is likely that a diver will increase breathing rate and decrease swimming speed. Estimation of gas quantities for reasonably foreseeable contingencies.Estimation of gas required for the planned dive, including bottom gas, travel gas, and decompression gases, as appropriate to the profile.Gas planning includes the following aspects: : Sect.3 In almost all cases this will be the surface. The purpose of gas planning is to ensure that for all reasonably foreseeable contingencies, the divers of a team have sufficient breathing gas to safely return to a place where more breathing gas is available. Use of calculated reserves based on planned dive profile and estimated gas consumption rates rather than an arbitrary pressure is sometimes referred to as rock bottom gas management. It may assume that the dive profile, including decompression, is known, but the process may be iterative, involving changes to the dive profile as a consequence of the gas requirement calculation, or changes to the gas mixtures chosen. Scuba gas planning is the aspect of dive planning and of gas management which deals with the calculation or estimation of the amounts and mixtures of gases to be used for a planned dive. Estimation of breathing gas mixtures and quantities required for a planned dive profile A decompression dive may require the use of more than one gas mixture An independent reserve gas supply in a pony cylinder A reserve valve will keep some air in reserve until the valve is opened Most recreational divers rely on their buddy to supply air in an emergency via a second demand valve