Lincoln's Secret Weapon

Student Handout

Planning Your Profile

Diving Guidelines
  1. When diving more than once a day, make the deepest dive first and the shallowest one last. This way, the largest amount of gas (gained from the deepest dive) is taken on early and can be lost over the longest period of time.

  2. When using dive tables, the deepest point during that dive determines the depth of a dive.

  3. When diving more than once a day, all dives of less than 40 feet (12.2 meters) are counted as 40-foot dives.

  4. Divers should not dive within 24 hours of flight time because airplane cabins are only partially pressurized, and any remaining dive gas will be released as the plane leaves the ground.

  5. So that you will not absorb an unsafe amount of dissolved gas, you cannot accumulate any more than 24 gas points per day.

Dive Schedule
Your team has made this schedule for the three days on the island. The first and fifth days are arrival and departure days.
  • 9 a.m., first morning dive
  • One-hour rest
  • Second morning dive
  • Three-hour rest
  • Last dive, late afternoon

Depth of dive Dissolved gas points per dive
Short dive Medium dive Long dive
40 feet
(12.2 meters)
1 3 12
50 feet
(15.2 meters)
2 4 18
60 feet
(18.3 meters)
3 6 22
70 feet
(21.3 meters)
4 9 26
80 feet
(24.4 meters)
5 12 30
Time at surface
After returning to the surface, divers continue to lose dissolved gas. Subtract 1 gas point for each hour of rest between dives.