Like pilots or sailors, skydivers log their activity and achievements in order to document their experience
Written records usually kept on a daily basis.
A log-book is a book kept in ships and into which the direction of the wind, course of the ship, state of the weather at all hours of the day, are daily transcribed at noon, together with every circumstance deserving notice that may happen to the ship or within her cognizance, either at sea or in a harbour, etc.
A log of everything to do with swimming, including all training sessions and event best times. To be
List of the dives a diver has recorded for proof of experience.