Yeah and like an idiot I didn't patent my idea years ago. I had actually made this exact same thing using a baby monitor that I got from Rite Aid. They use these to warn mothers if their kids venture more than a certain number of feet away. I hooked the buzzer to a grounding relay on the boat ignition circut. Wa-La same deal for $20.00 Of course this would only work for one person. But then I had a center console Grady White and usually it was just me out fishing in the Ocean. I also figured other uses for it like farmers on tractors, and Aircraft refueling trucks. I worked in aviation for several years at an airport. If the guys walked away while the fuel truck was hooked up and the engine was running it would shut the truck off. etc, etc.......Stupid me.
