Subsurface is an open source divelog program that runs on Windows, Mac and Linux

Screenshot of a recreational dive

Log all your dives

Download your dives from your dive computer. Import them from other dive log programs or dive log websites. Manually enter them directly in Subsurface or via a simple spreadsheet.

Screenshot of a recreational dive

Dive planner

The planner module makes it simple to visually plan dives either based on Bühlmann ZH-16 or VPM-B

Screenshot of a recreational dive

Cloud storage

Store your logbook data in the cloud. Work with your data from different computers, online and offline. Fully integrated, free, and easy to set up.

Subsurface can track single- and multi-tank dives using air, Nitrox or TriMix. It allows tracking of dive locations including GPS coordinates (which can also conveniently be entered using a map interface), logging of equipment used and names of other divers, and lets users rate dives and provide additional notes.

Users can tag dives and filter a dive list based on criteria including tags, locations and people with whom you were diving.

Screenshot of rating, tags and other data fields

Subsurface also calculates a wide variety of statistics of the user’s diving and tracks information like the SAC rate, partial pressures of O2, N2 and He, calculated deco information, and many more.

The program is localized in about 20 languages and well supported by an active developer community.

One of the major strengths of Subsurface is its support of a wide range of dive computers (see the list of supported dive computers). Subsurface can also import existing dive logs from several sources including MacDive, Suunto DM3, DM4 & DM5, JDiveLog and

Another strength is its ability to visualize the depth profile (and, if available, the tank pressure curve) in innovative ways that give the user additional information on relative velocity, and momentary air consumption, during a dive.

Screenshot of dive profile

Subsurface lets the user print out a detailed log book including dive profiles and other important information.

A bit of background:

In fall of 2011, when a forced lull in kernel development gave him a chance to start a new project, Linux creator Linus Torvalds decided to tackle his frustration with the lack of decent divelog software on Linux.
Linus worked with a team of developers, and Subsurface is the result. It now supports Linux, Windows and MacOS and allows data import from many dive computers and several existing divelog programs. It provides a quick and easy way to see the key information provided by a modern dive computer and lets users track a wide variety of data about their dives. In fall of 2012 Dirk Hohndel took over as Subsurface maintainer.
License: GPLv2