On a calm night off the east coast of Australia a few years back, 10-year-old Simon Pallister fell off the family sailboat. It took one hour for  Pallister's parents to notice his absence and another eight for a helicopter crew to locate the victim and dispatch a fishing boat that picked him up, luckily, alive.

This horrifying event motivated Simon's father, Mark, to invent MOBi-lert. When it hit the market in 2004, MOBi-lert was the first man overboard alert system of its kind, relying on a closed-loop radio circuit to monitor the status of crew. If a crewmember wearing a transmitter pendant falls overboard, the pendant loses touch with the onboard receiver, triggering an alarm and, depending on the setup, marking the location of the MOB incident on the boat's chart plotter

Fast forward to 2008, closed-loop MOB alert systems are quickly becoming standard safety equipment on racing sailboats, cruising boats, commercial vessels, you name it. Mark Pallister is no longer with Mobilarm, and Mobilarm is no longer the only player in the market--companies such as Wavefinder, Seamarshall, ACR, and the marine electronics powerhouse Raymarine have all come out with versions of Pallister's invention--but this small, Australian company continues to drive MOB technology forward.

Speaking with Mobilarm's Peter Gedye, I was surprised to learn that the mounting competition has actually been good for business. "As soon as Raymarine came out with their system, that helped us spread the word," says Gedye. "As a small company, it's hard for us to educate the whole marine market that these products can in fact save your life."

"The reason we're not too worried about the competition [from Raymarine] is that they've put together a very basic system," says Gedye. "Feature-wise, our system is a bit more rich."

Intended for use on fiberglass boats up to 45 feet long, Mobilarm's MOBi-lert 720i retails for $895 and includes two pendants with rechargable batteries, a pendant charger, an alert console, and an antenna. Raymarine's LifeTag system, which retails for $685, comes with a similar array of components, but doesn't have some of the more advanced features you'll find on the MOBi-lert 720i. The main advantage of the 720i is its detailed alert console, which displays the status of up to six pendants and allows you to check battery power, signal strength, and GPS connectivity at a glance. The LifeTag system only displays visually if connected to a Raymarine C- or E-series chart plotter, while the 720i integrates with any NMEA 0183-compatible GPS plotter, including products by Raymarine, Furuno, NavNet, Northstar, Garmin, and others. As soon as an incommunicative pendant triggers the alarm, the system will automatically mark a waypoint for the location at which the MOB incident occured.

Rechargable batteries are another feature of the 720i that racers may come to appreciate. "When you're at sea, the last thing you want to do is open your pendant to change the batteries," says Gedye. "Between the salt in the air and the water flushing across the deck, nothing good can come of it."

The 720i incorporates a slight delay between the time the pendant goes incommunicado and the time the alarm sounds, which should reduce false alarms that occur when the pendant-wearer gets doused with a wave. The system also has an MOB-activated secondary relay that you can program to switch the boat's autohelm to circle mode, shut off the engine, or activate an EPIRB.

Mobilert seems to have left no stone unturned when it came to optimizing the 720i with safety features. During MOB recovery, the sound of the alarm changes as the boat approaches the victim. Gedye explains the reasoning behind the proximity alarm: "This way, you won't have to return to shore and say, 'We found the bugger, but we couldn't rescue him becase we ran him over.'"

www.mobilarm.com