The Alert2 offers features that make it a good choice for coastal/offshore boating. It has a number of extra features such as an optional radio direction finder (RDF) which enables the user to search for the transmitter’s radio signal when retrieving the crew-overboard. This could be a life-saving feature in rough conditions or low visibility. It also has the ability to be wired into your GPS and chartplotter to mark the position where the crewmember went overboard. As with any GPS man-overboard waypoint, it cannot account for drift occurring after activation.

    The second system we tested was the Virtual Lifeline which also had a quick response time similar to the lanyards. Its water-activated sensors immediately sounded an alarm and quickly cut the engine when submerged. We timed 6.25 seconds between dropping the sensor in the water and ‘rest’ - just a hair longer than the Alert2 and lanyards. It is an excellent choice for use with families and larger groups that are boating on inland and protected waterways. Its water-activated sensors can also be used as a precautionary mechanism. When swimmers are in the water they could each wear one of the sensors so you can’t restart the engine until everyone is on board.

    Both of these water-activated models caused us to question the likelihood of fasle activation from rain or spray. We tested the transmitters of each and found out that they must be submerged to activate. Each one has safeguards built-in to prevent a false activation from a small amount of water from normal boating spray. The Alert2 has a protective holster which covers the sensor and the Virtual Lifeline has a similar protected entry point for water.

    The third wireless unit we tested, the MOBi-lert, is primarily a crew-overboard alarm device that works by sensing a disruption in the radio signal between the sensor and the base unit. This occurs when the sensor goes outside the range of the signal or is submerged in water. The kill-switch unit that we tested was a prototype made specifically for us and is not yet commercially available. The manufacturer said that the unit may be released as an optional add-on for retail sale later in the year. 
According to the manufacturer, there is a built-in delay to prevent a false activation, and a second delay on the engine cut-out unit. We timed 11 seconds between the time the sensor went in the water and the alarm. Ten seconds later the engine cut and the boat came to ‘rest’. This convenient delay between alarm and engine-kill allows the boat operator to turn back and pick up the crew-overboard without having to restart the engine. Since the MOBi-lert’s multiple sensors are always on, you’ll always know when your crew is on board. You could even use it to keep track of your crew when in port and make sure you don’t leave anyone behind.

    The MOBi-lert is well-suited for coastal and offshore boating as it can also be connected to a GPS or chart plotter and will automatically trigger a crew-overboard waypoint if someone falls into the water.