Rock Bottom Calculator

Rock bottom also commonly known as minimum gas (MG) is the gas required for two divers to ascend from the bottom to the first available gas source while sharing one source. For the typical recreational dive the first available gas source is usually the surface. While that may also be true for a technical or cave dive the first available gas source could also be a technical diver's decompression gases, or a stage bottle dropped in the cave by a cave diver.

Note: This calculator is for my personal use only! Divers should complete the necessary dive training by an official agency and appropriately qualified instructor to calculate and determine their own minimum gas required.

This calculator assumes the following...


  • Ascent Rate: 30 ft/min (Depths greater than 30 ft), 10 ft/min (Depths less than 30 ft)
  • Max Depth: Deepest portion of dive expressed in feet.
  • Time: Time needed to solve the problem at deepest portion of dive expressed in minutes.
  • SAC: Surface Air Consumption rate expressed in cubic feet per minute.

Max Depth:

Time:

SAC:




Admiralty Inlet

  • Wednesday
    10/18/2017
  • 4:57 PM - Slack Ebb

  • Thursday
    10/19/2017
  • 12:13 AM - Slack Flood
  • 5:50 AM - Slack Ebb
  • 12:25 PM - Slack Flood
  • 5:28 PM - Slack Ebb

  • Friday
    10/20/2017
  • 12:48 AM - Slack Flood
  • 6:37 AM - Slack Ebb
  • 1:10 PM - Slack Flood
  • 5:55 PM - Slack Ebb

  • Saturday
    10/21/2017
  • 1:22 AM - Slack Flood
  • 7:21 AM - Slack Ebb
  • 1:53 PM - Slack Flood
  • 6:20 PM - Slack Ebb

  • Sunday
    10/22/2017
  • 1:56 AM - Slack Flood
  • 8:02 AM - Slack Ebb
  • 2:39 PM - Slack Flood

The Narrows

  • Wednesday
    10/18/2017
  • 5:47 PM - Slack Ebb

  • Thursday
    10/19/2017
  • 12:11 AM - Slack Flood
  • 6:27 AM - Slack Ebb
  • 12:31 PM - Slack Flood
  • 6:20 PM - Slack Ebb

  • Friday
    10/20/2017
  • 12:51 AM - Slack Flood
  • 7:14 AM - Slack Ebb
  • 1:16 PM - Slack Flood
  • 6:51 PM - Slack Ebb

  • Saturday
    10/21/2017
  • 1:28 AM - Slack Flood
  • 7:57 AM - Slack Ebb
  • 1:59 PM - Slack Flood
  • 7:20 PM - Slack Ebb

  • Sunday
    10/22/2017
  • 2:04 AM - Slack Flood
  • 8:39 AM - Slack Ebb
  • 2:41 PM - Slack Flood

Current & Tide
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Current
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