Re: destroyed impeller
I like the idea of a sensor on the input valve to start the engine. But, I usually prefer the simplest solution, the fact is I have NEVER done this before. I always open that valve and then check for the flow out of the exhaust before leaving my dock. But I was not at my dock and there were lots of distractions; the kids, other boats and backing out of a runway. Enough excuses, I messed up, but recovered. The boat next to me in the dock could not believe I changed the impeller while out in the channel, when I told him later. We missed the first race, but made it into the second. It actually worked out better as it gave me some time to work my new crew thru some tacks and jibes.
I can only assume my overtemp sensor went off before there was any real issue with the engine (what is the issue with on overheated diesel - running on?). I never saw any smoke or other indication of a problem with the engine. The engine always started right up as I was looking for the source of the problem.
I store my engine key close to your suggestion, it is on the steps I have to remove to open the water intake valve. But not close enough this time.