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Electronic lifelines: MOB insurance

High-tech personal safety devices are making rescues quicker and easier when the unthinkable happens

Accidents happen every day on the water. I’ve had some experience being in the water as the boat appears to get smaller and smaller on the horizon. No one expects to fall overboard and end up in a possible life-or-death situation, but it can and does happen. If the unthinkable took place, would you be prepared?

There are numerous low-tech products designed to be used in an MOB situation, but the newest electronic alerting technology is designed to make these potentially life-threatening accidents less risky. Several companies have developed electronic safety devices focused on this age-old problem.

This roundup comprises LifeTag, ACR's ResQFix PLB and AutoTether.AutoTether is a wireless lanyard system that, in its simplest form, will shut down any typical kill-switch-equipped outboard boat if the operator goes overboard. The system eliminates the obtrusive and movement-restricting conventional red kill-switch lanyard. The LifeTag system from Raymarine is a wireless MOB locater that uses an audible alarm to signal the boat and activates the MOB function on compatible SeaTalk-enabled Raymarine chart plotters and networks. ACR’s ResQFix GPS personal locator beacon (with internal GPS) will transmit an MOB’s position and personalized identifier code through the COSPAS-SARSAT satellites, alerting SAR authorities that you need rescue.

I’ve examined these three products on board and at the workbench. Here’s what I found:


The AutoTether system shuts down the engine if a person wearing a sensor falls overboard.I used the AutoTether system aboard my twin-engine Boston Whaler center console, which is equipped with a single kill switch that shuts down both outboards simultaneously through a single lanyard. The AutoTether system consists of a host unit — a self-contained transmitter/receiver — two remote FOBs (personal sensors) worn by vessel occupants, batteries and attachment hardware.

Using bright, two-color-capable LEDs, the host display indicates system power, alarm condition and reset, along with the number of FOBs that have been switched on. While two FOBs are included with the system, it can monitor up to four per host unit. A 12-inch coiled wire and integral, solenoid-activated, spring-loaded ignition kill-switch clip are designed to replace the red lanyard, which, along with the FOBs, eliminate the hassle of people being physically connected to the boat.

The host unit attaches to the boat’s console using hook-and-loop fasteners, and it needs to be clearly visible to the operator and within 12 inches of the vessel’s emergency kill switch. It measures 3-3/4 by 2-3/4 by 3/4 inches and is water-resistant to 3 feet, so it

shouldn’t be difficult to locate a good installation spot.

FOBs are designated as “operator” (yellow) and “passenger” (white), because they perform different functions. If an operator FOB is submerged for 0.5 seconds, the host triggers the AutoTether audible alarm and shuts off the engines by activating the spring-loaded AutoTether kill switch. If a passenger FOB is submerged, it will trigger only the host unit’s audible and flashing-light alarm. The passenger MOB alarm doesn’t disable the engine, allowing the operator to maneuver and pick up the person who has fallen overboard.

Measuring 3 by 1-1/2 by 3/4 inches — smaller than most cell phones — and weighing 2.15 ounces, the FOBs have detachable clips that can be attached to swim trunks or clothing, but they do not float. Velcro-style straps are also included.

I easily threaded the white passenger FOB to a conventional PFD strap and clipped my yellow operator FOB to the harness of my inflatable PFD. The manual warns against covering an active FOB with clothing, PFD, towel etc., as it may cause signal disruption and inadvertently trigger the alarm. I experienced no signal disruption during my testing.

I appreciate the fact that both the FOBs and host unit are screwed together, requiring a tool to access the batteries. Screws allow for a positive and secure seal without damaging the case halves, as often occurs by using coins or other devices to open cases. The screws are captive in the case to avoid misplacing them, and the thin silicone O-ring has a shoulder to assist in alignment. The included 12 AAA batteries (six in the host, three in each FOB) are good for 150 hours of use, according to the company, and that should get most of us through a full season of boating.

When the host is properly installed and activated, it automatically establishes communication with the active FOBs and continuously monitors each one. The FOBs cannot be turned off manually, which prevents them from being unintentionally disconnected from the system. In an emergency, you can hold the “off” button on the FOB for more than two seconds, activating the AutoTether audio alarm, triggering the spring-loaded kill-switch clip, and shutting off the vessel’s propulsion. That is the only time the white FOB will shut down the engine. Each FOB will shut off automatically after the host is powered down.

So long as the host is mounted within the operator’s line of sight, the alarm-mode LED activation is significant enough to call your attention to the unit. The audible alarm, however, was disappointing. The low volume of 71DBc at three feet is due in part to the buzzer being mounted within the splash-proof enclosure of the host. It’s great that the system is totally self-contained and portable, but I would appreciate a louder internal buzzer that can be clearly heard over engine noise and an auxiliary output that would allow connecting the device to the boat’s horn or other signaling device. More on that later.

Basic system activation, testing and operation are straightforward, but reading the owner’s manual is a must. Aside from the obligatory safety disclaimers and FCC regulations, there are 14 pages of valuable information in the well-written manual.

The host has multiple LED indicators that confirm the status of the system, which FOBs are active, the battery condition, alarm condition, and any system faults. All system indicators are clearly described in the manual, but I would also appreciate a small waterproof “cheat sheet” that quickly guides the infrequent user through setup and decoding the indicator lights in the event of system alarm or fault.

My initial concern with a device such as AutoTether is the potential of inadvertent engine shutdown because of false alarms induced by splashing the FOB. Anthony Viggano, inventor of AutoTether, assured me that more than two years were spent developing the software to assure AutoTether’s reliability, working out such issues as accidental discharge and radio-signal interference. There are more than 3,600 lines of code written into the AutoTether software, and the units have serialized numbering, allowing future software updates.

To confirm the practicality of the FOBs in adverse conditions, I held both FOBs under running water for extended periods without activating the alarm. However, they activated the alarm quickly when totally submerged in water. Viggano says the host and FOB communicate using 16-bit code. Submersion in a large body of water blocks the transmission of data, but the FOB is not activated by brief splashing. When the FOB is hit by a wave, some data is transmitted, but the host knows the FOB is not under water and doesn’t go into alarm mode. The system requires three consecutive missed transmissions of less than 80 percent of code for activation.

After using AutoTether, my thoughts immediately went to how I can adapt it to my diesel trawler, which has no kill switch. And what about a sailboat? All boats and operators can benefit from this relatively inexpensive safety add-on. Viggano has been working on such options, and the company can provide an accessory switch and related circuitry or diagrams that can adapt AutoTether to perform almost limitless alarm responses, such as disconnecting an autopilot, sounding horns and flashing lights. There’s even a version that is connected to a handheld air horn if you’re looking for a really loud alarm.

As a tender anti-theft device, you could place one of the FOBs in your dinghy at night and set the host by your bunk (remember, it’s portable). If someone moves your tender and goes beyond the system range of 150 to 200 feet, the alarm will sound.

AutoTether works as advertised and certainly enhances the safety of the operator and passengers. It’s a cost-effective means of dealing with a potential MOB situation. It operates independently of any other on-board electronics, yet can be incorporated into larger and more complex systems.

AutoTether seems the perfect MOB device for anyone who spends time single-handing. Whether fishing, cruising or taking the kids tubing, knowing that the boat will shut down and be there for you to reboard should you go over the side is a comforting feeling. It is manufactured entirely in Connecticut, and with an office staff of four, including Viggano, you’re certain to speak with someone having firsthand product knowledge should you need assistance.

This retail price is $295 for the standard AutoTether with two FOBs. AutoTether offers a “Solo Fisherman” version with one FOB for $235 and the wireless handheld air horn model for $375. Additional FOBs are available for $69 each. Engine-specific adaptors for the actuator are included. Visit www.autotether.com to purchase directly or for a list of retailers.

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