 When decompression planning software is used to produce a schedule for a planned dive, the necessary input includes a definition of the dive profile.This may be in as much detail as the user is prepared to provide and the program is capable of using, but will always specify at least maximum depth and bottom time, and may go into detail regarding recent dive history, multiple levels, gas switches, altitude and personal conservatism factors.Many dive computers have a dive planning function for which the diver selects a maximum depth and the computer displays the maximum bottom time for which no decompression stops are required.