After smoke, carbon-monoxide, and high-water alarms, it’s likely that the engine’s low-oil-pressure alarm is among the most important in your quiver of vessel alerts. An engine can be seriously or irreparably damaged if it’s run without oil pressure for just a few seconds. Fortunately, this alarm has its own built-in test feature that’s activated with each start-up. If the alarm sounds with the key on and the engine not running, then goes silent when the engine starts, all is working properly. Once the engine has started and oil pressure has silenced the alert, then, assuming that the wiring and components are sound, only one thing can trigger this warning signal: low or no oil pressure. Simple—and critical—as this system is, I’m amazed at how many of the vessels I operate have no working low-oil-pressure alarm. On your own boat, if you don’t hear that alarm on start-up, troubleshoot the reason immediately, as you’re running without protection from this potentially catastrophic engine killer, the lack of lubricating oil.