page_title: Scuba gas planning
hierarchical_section_title: Scuba gas planning
caption_attribution_description: English: Draeger 200 bar taper thread DIN cylinder valves with reserve lever assembled with manifold on twin 7 litre steel cylinders
context_page_description: Scuba gas planning is the aspect of dive planning which deals with the calculation or estimation of the amounts and mixtures of gases to be used for a planned dive profile. It usually assumes 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. 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. 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. In almost all cases this will be the surface.
  Gas planning includes the following aspects:
  Choice of breathing gases
  Choice of Scuba configuration
  Estimation of gas required for the planned dive, including bottom gas, travel gas, and decompression gases, as appropriate to the profile.
  Estimation of gas quantities for reasonably foreseeable contingencies.
context_section_description: Scuba gas planning is the aspect of dive planning which deals with the calculation or estimation of the amounts and mixtures of gases to be used for a planned dive profile. It usually assumes 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. 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. 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. In almost all cases this will be the surface.
  Gas planning includes the following aspects:
  Choice of breathing gases
  Choice of Scuba configuration
  Estimation of gas required for the planned dive, including bottom gas, travel gas, and decompression gases, as appropriate to the profile.
  Estimation of gas quantities for reasonably foreseeable contingencies. Under stress it is likely that a diver will increase breathing rate and decrease swimming speed. Both of these lead to a higher gas consumption during an emergency exit or ascent.
  Choice of cylinders to carry the required gases. Each cylinder volume and working pressure must be sufficient to contain the required quantity of gas.
  Calculation of the pressures for each of the gases in each of the cylinders to provide the required quantities.
  Specifying the critical pressures of relevant gas mixtures for appropriate stages (waypoints) of the planned dive profile.
  Gas planning is one of the stages of scuba gas management. The other stages include:
  Knowledge of personal and team members' gas consumption rates under varying conditions
  basic consumption at the surface for variations in workload
  variation in consumption due to depth variation
  variation in consumption due to dive conditions and personal physical and mental condition
  Monitoring the contents of the cylinders during a dive
  Awareness of the critical pressures and using them to manage the dive
  Efficient use of the available gas during the planned dive and during an emergency
  Limiting the risk of equipment malfunctions that could cause a loss of breathing gas
caption: A reserve valve will keep some air in reserve until the valve is opened
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