Hello

I have a stand-up paddleboard to which I have attached a 12 volt trolling motor. I'm in need of a kill switch that is proximity activated so when I leave a determined radius, power is discontinued. I would like to attach the wireless trigger to my life vest.

 

Doable.
I would suggest looking into a magnetic reed switch first. A magnet tied to a lanyard is a simple solution that should not be ignored.

 

Doable.
I would suggest looking into a magnetic reed switch first. A magnet tied to a lanyard is a simple solution that should not be ignored.

…which doesn’t depend on an electronic circuit that could fail from the moisture and permanently supply power / continuity to the motor.

 

Look up "lanyard kill switch".
You'll find numerous examples.

 

If none of those suggested can be found, many boats use such to kill the engine if the driver falls out. So a marine supply shop should have one made for the application. Avoid a trailer breakaway switch because they switch ON when the lanyard is pulled..
And a wireless is about the most likely to fail at the worst possible time.

 

Thank you all for your replies,

I am trying to avoid using a lanyard/leash for safety reasons but it is looking like the technology isn't there for a reliable wireless option.

I think I will go with https://waterblade.net/Views/ProductDetails.aspx?ID=81 and a leash because this unit disconnects the power supply without needing a control module.