Suunto D4 is a full-decompression wristop dive computer designed to put information, ease of use, and style first. Its four operating modes, dive planning and analysis functions, and compatibility with optional Suunto Dive Manager PC software make Suunto D4 a great choice for those who value functionality and ease of use.

With its innovative freedive functions and dedicated freedive mode, Suunto D4 is also perfect if you're serious about breath-hold diving. Programmed to sample depth three times a second, Suunto D4 records highly accurate data on the true depth reached. Surface time and depth alarms help you make responsible decisions both in and out of the water.

In both Air and Nitrox mode, the clear, easy-to-read screen can display your current and maximum depth; current time, dive time, and decompression time; and temperature. Audible and visual depth and time alarms warn you when it's time to start your ascent. In Nitrox mode, you can increase your time underwater by adjusting the oxygen content of your gas between 21% and 50% and adjust your PO2 limit between 0.5 and 1.6 bar.

Like other advanced Suunto dive computers, Suunto D4 uses the Suunto RGBM algorithm for decompression calculations. It also allows you to choose between taking traditional safety stops or, with the Deep Stops feature activated, taking your safety stops at depth.

Before diving, the no-stop-time planner helps you prepare for your dive. Enter the planned maximum depth of your dive, and Suunto D4 will tell you how long you can dive before needing a decompression stop. After diving you can instantly review all the data in the logbook. Suunto D4 is also compatible with the optional Suunto Dive manager PC software, which provides more in-depth analysis and graphical representation of all your dives.