Then to the question, we don't check the generator every two hours during the night. We do have alarms for water, fire, temperature, and everything else we can think of. ... We check the ER before going to bed and upon waking.
I've been thinking about this thread while doing my diesel clean-up from the genset problem. Luckily it didn't happen underway, luckily it didn't flood the engine room enough to start pumping diesel overboard...
(This wasn't like a normal slow leak from a loose fuel hose; more like what would happen if the metal receptacle -- that holds a spin-on filter -- cracked. That description is technically inaccurate; it didn't crack, but one of the ports, a metal piece that I had thought was an integral part of the casting, almost ejected itself.)
If I had been doing hourly checks... that would not have been often enough; bilge pumps would have activated, diesel overboard, downhill very fast from there. We too seldom do frequent checks on the generator when we're just hanging around at anchor, and we seldom run it overnight anyway. (In this case, it was just Spring start-up, normal systems check, at the dock...)
The bilge pump warnings might have gotten my attention -- had I been on the bridge -- but by then it'd be too late for that overboard thing. The high water alarm would certainly have gotten my attention -- again, too late.
A camera (or cameras) in the engine room... maybe, although I'd have had to keep my eyes glued to the display to notice this particular incident early enough. And it (or they) would have had to be aimed at just the right place. And the display would have to be near where I was; display on the bridge, with me doing some other chore in the saloon... no good.
Maybe another high water alarm, mounted lower. Or I could maybe remount the existing sensor, low enough to give an earlier warning... but that still could have allowed a boatload of diesel in the bilge...
I'm still trying to analyze my way toward a better solution...
-Chris