Of course, as with any racing watch, the most critical function of the Mariner is to tell you how much time until the gun. In Sailing Timer mode, the watch displays both the time of day and a countdown timer. I like having this split screen when sailing around before the start. At a glance, I can tell how long I have until the race committee is supposed to start its sequence and I can verify that I have my timer ready to catch the five-minute gun. Once in sequence, the timer beeps at logical intervals, so you don't necessarily have to look down at the watch every fifteen seconds. If you were late on the five-minute gun, you can catch the four-minute gun by pressing the sync button, which restarts the timer at the nearest minute. As a fail-safe against accidental deactivation, it takes two firm presses of the start/stop button to halt the countdown. After the start, the countdown timer automatically starts counting up, allowing you to record and recall split times in the Sailing Timer Memory sub mode. This feature might be helpful for tracking waypoints in a distance race or figuring out corrected time in PHRF, but I doubt I'll ever use it.