Surface Consumption Rate

The Surface Consumption Rate (SCR), also known as the Surface Air Consumption (SAC) rate, is a measure used by divers to calculate the amount of gas a diver consumes per minute while at the surface. This rate is crucial for planning dives, especially when determining how much gas is needed for a dive and for emergency situations.

The SCR is typically expressed in liters per minute (L/min) or cubic feet per minute (cfm). It can be calculated by measuring the diver’s gas consumption rate at a specific depth and then adjusting that rate to account for surface pressure. The SCR helps divers estimate how much air they’ll use during a dive, allowing for better dive planning and ensuring adequate air supply.

To calculate the SCR from your dive

  1. Used air (bar) × Tank size ( 11.1ℓ / 12ℓ etc )= Used Air (ℓ)
  2. Used Air (ℓ) ÷ Run time ÷ ATA at the average depth = SCR (using air per minute at one atmosphere)

By using the SCR, divers can better manage their air supply, ensuring safety and more efficient dive planning.