Course Outline

After the first dive, the following details are known.

  • TOD: 15 m/49 ft.
  • Dive time: 40 min. (from surface to leaving the bottom to begin ascent, excluding ascent and safety stop time
  • Air supply: 40 bar/588 psi (the supply at the end of the dive on surfacing)

Calculating SAC

SAC is calculated by using the following information.

  • Gas used: 160 bar/2,412 psi or 1,776 L/64.32 cu. ft.

    Metric

    160 bar × 11.1 L = 1,776 L

    Imperial

    80 cu. ft. × 588psi ÷ 3000 psi = 15.68 cu. ft.


    80 cu. ft. - 15.68 cu. ft. = 64.32 cu. ft.

  • Time: 45 minutes

    40 min. (Dive Time) + 2 min. (Ascent Time) + 3 min. (Safety Stop Time) = 45 min.

  • Average depth: 12 m/39 ft./2.2 bar
  • Metric

    Divide liters by minutes to get RMV.

    1,776 L ÷ 45 min. = 39.47 L p/m (RMV)

    Now, divide RMV by depth to get SAC.

    39.47 L ÷ 2.2 bar = 17.94 L p/m (~18 L p/m) (SAC)

    Imperial

    Divide cu.ft. by minutes to get RMV.

    64.32 cu. ft. ÷ 45 min. = 1.43 cu. ft. p/m (RMV)

    Now, divide RMV by depth to get SAC.

    1.43 cu. ft. p/m ÷ 2.2 bar = 0.65 cu. ft. p/m (SAC)

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