Keep dive session logs, using also on line info, with Subsurface
Subsurface is a free and easy program you can use to log your diving sessions, even import data from several file formats (CSV, CAN, JLB, LVD, DLD, SDE, UDDF, DLF, XML and more), get GPS data locally or on line.
The program features tab sets letting you keep notes, dive information, photos, etc. According to the data you write down Subsurface is able to warn you for oxygen level and medical issues, etc. It is able to plan and track single- and multi-tank dives using air, Nitrox or TriMix.
Subsurface helps you to add location coordinates, temperature, dive types, information on your equipment, and much more. If you dive with multiple computers you are able to combine data from several computers into a single dive. You can export data you entered in Subsurface in formats you can use with other programs.
If you dive systematically, Subsurface is not a program you can ignore.