I have no "key" for my boat. What I have is a double-switched ignition circuit.
I have a push-pull switch in the cockpit, with the pushbutton start and the choke and throttle. On the same circuit, I have a push-pull on the main electrical panel down below. Both of these push-pull switches must be closed for the engine to run or start.
The only theft-deterrant is the lock on the companionway slide, but that's enough for me. On the plus side, there's no key to lose.
The other plus is that a person down in the cabin has the ability to easily kill the engine in the event of fire, etc... As a matter of convenience, it's handy for start-stop operations during engine maintenance. This would also work for diesels with an electric fuel solenoid, but I imagine it might be tougher to rig for those with the pull-cable fuel cutoff.
Tim and I discussed this a while ago, but I got enough "hey now" comments from the dockbirds over the course of the weekend that I thought it worth passing along to others.
Engine circuit
Bypassing the ignition switch...
I have always been concerned about breaking the key off at a crutial moment or losing the thing altogether so I also bypassed the ignition switch.
I make the circuit hot with a red switch near the companionway and push the start button to start the Yanmar. I also break both the postion and negative connections to the engine when the boat is hooked up to shore power.
I make the circuit hot with a red switch near the companionway and push the start button to start the Yanmar. I also break both the postion and negative connections to the engine when the boat is hooked up to shore power.