Monday Minute - Safety on the Water using IoT


In a clever and cool application of Internet of Things (IoT) and Bluetooth connectivity of two electronic devices for marine safety, Weems & Plath introduced a new product at the U.S. Sailboat Show in Annapolis. The CrewWatcher uses a smartphone app to connect up to five small orange transponders.

Completely independent of a need for WiFi, Internet, or even cell service, the concept is brilliantly simple. Each small orange transponder, about the size of a floating key fob, attaches to a crew member, a pet's collar, or on a PFD. The CrewWatcher app, once installed in your smartphone or tablet, is turned on, and automatically pairs to each transponder using low-energy Bluetooth. You can assign names to each transponder so you know who it belongs to. The CrewWatcher app is left on, in the background, while you use the phone/tablet for navigation or other uses. The app continually polls each transponder to make sure it remains connected between the devices.


Should a transponder travel far enough away from the app to lose the Bluetooth connection, the alarm will sound as loud as possible, overriding any sound level setting in the device, even if it is set to mute. The alarm also flashes a strobe light using the device's flash, as well as vibrate the device.


In addition, if the transponder is immersed in water, such as a dog or crew falling into the water, the app sounds the alarm immediately. Bluetooth does not work very well through water, so the connection is quickly lost in a person overboard event.

The app will show where the transponder was lost on a visual compass screen, and aid returning to the point where it lost the unit's signal, using no input from the transponder. Battery life of the transponder is about three years.


The demonstration of this system was pretty slick, modern technology at its best. The developers, Pan Pan B.V. of the Netherlands, have really thought this through, and representatives of the company were on hand to explain they plan even more functionality in the future. IoT devices and connectivity applications will explode in the coming years, and this is a ground breaking example of using the devices you already have for even greater utility. We've come a long way in mobile phones!

The CrewWatcher provides a low-cost safety device for up to five transponders on your boat. A single CrewWatcher costs $89.99, and there is a discount for packs of multiple transponders.

The Bluetooth connectivity technology operates much faster than AIS or traditional signaling devices, and takes advantage of what you already have onboard. Most cruisers have smartphones, and many use tablets for navigation and other purposes.


I think this is just the start of new product lines and safety gear that use connectivity to make boating safer without the need for additional expensive investment in equipment. I think you can see how it would be a lifesaver in situations where you don't have your eyes on everyone all the time.

For more information, go to the Weems & Plath website at