Useful on crewed vessels, man overboard alarms sound when a person goes over the rail. A belt and suspenders approach to crew safety would be to combine one of these devices with use of a personal locator beacon (PLB). Since man overboard alarms are meant to alert others onboard, a single handed sailor is not going to get much benefit from many of these devices. Crews should practice man overboard procedures regularly.
Raymarine LifeTag Wireless Man Overboard System uses radio frequency technology to watch over crew members and sounds an alarm if anyone moves out of range (about 30 feet). The LifeTag wireless pendant straps to the arm and there can be up 16 tags used with the system. Using Raymarine proprietary SeaTalk integration system, data from an activated LifeTag is transmitted and displayed Raymarine multifunction displays. This places search and rescue data right in the wheelhouse where it is needed. Suggested retail price for a basic system is $685USD.
First Light Solutions mermaid id man overboard system uses digital sonar technology to ensure crew safety. Each person onboard wears a id-pod device. Once an id-pod makes contact with the water, an alarm is sounded at the helm. Once the alarm is raised, the mermaid id system uses a LED display to provide course guidance back to the position of the person in water. First Light is actively exploring installation of this technology on vessels that will participate in the Volvo Ocean Race.
Mobilarm MOB-ilert is a crew monitoring system designed to facilitate a rescue in the event of a man overboard emergency. Each crewmember wears a PTX transmitter that maintains constant contact with the vessel. Once interrupted by a fall into the water, the boat's position is fixed by GPS and track-back data is provided at the helm. Remember GPS positions are static and a person in water will move somewhat with the wind and tide.
Emerald Marine Products Alert 2 System uses a water activated radio frequency transmitter that sends a coded signal to an onboard receiver. If a person falls in the water, an alarm is sounded at the helm. Using an optional interconnect kit, GPS data can be provided to mark a waypoint position. The Alert 2 transmitter lists for $239USD and onboard receiver is $499USD.Emerald sells an optional handheld direction finder that allows the user to locate a person in the water. This is would be especially helpful in heavy seas or foul weather were you could use sight of the victim. One feature of interest to solo sailors is an option that will kill the engine after a fall over the rails.
Man overboard warning systems can greatly improve crew safety on your vessel. A few safety reminders are in order. Unlike a PLB, these devices do not automatically contact search and rescue authorities. Devices that use track back data derived from GPS do not compensate for the effects of wind or tide on the person in the water. You need to anticipate these forces in your rescue plan. Solo sailors should consider using a PLB and an engine kill device or this same option offered by the Alert 2 device.
