I hadn't been to the boat in about 3 weeks do to one thing or another. Probably the longest time I had not been down to the boat to at least start the engine and check things. Anyway, plan was to prepare her for a trip we are planning to take after the July 4th Holiday up to Sacramento. It’s about a 200NM round trip through the Sacramento/San Joaquin Delta and River system.
Did the usual before starting, check oil level , check cooling water level, start engine, no problems. I took her over to the fuel dock to top off the tanks. I decided to take a little ride to give her a good run not having been out for 3 weeks. Bring her up to about 2800 RPM and within a few seconds the exhaust light comes on !!!!%^%^%^%&%^%!!!!. Mind you at this point I'm in Oakland inner harbor, a very busy place where all the boats from China come in and unload, but with luck, it' not that busy of a day, the current it slack and hardly any wind (very lucky). So I can take my time to figure things out. I shut the engine down immediately. Open up the engine box and take a look around, no leaks that I can see. Decided to start the engine and within a few seconds the exhaust light is back on, I also had been monitoring the temps gages before the exhaust light came on and it looked normal. Looking around while the engine is running and still no leaks. Shut her down, and decided to check the raw water intake strainer, all looked good there. I checked the exhaust port while at idle and it’s spitting water like it usually does. So the water pump and impeller seem to be working but exhaust light and alarm are on and blaring away. Did a quick check of all sensor wiring that I could locate to see if anything was loose.
A sail boat came by that saw me floating in the middle of the channel and checked in with me, I thanked them for their concern and since I was in no dire straights at this point waved them off. Decided to call vessel assist and finally use my tow insurance, I got to admit , I very nice thing to have! While waiting for the tow to arrive I called my mechanic and discussed things with him. We overhauled the cooling system about 3 years ago but it still could be just about anything. A failed sensor or connection to some kind of possible blockage in the raw water colling system.
I plan to go back to the boat today to see if I can find anything obvious in the electrical system. Mechanic will be on the boat Monday morning to check things out if I cannot find anything.
If anyone has had any experience with this kind of issue please chime in. I dod a quick check of the maintenance forum and could not find anything there except for one of my posts when we overhauled the cooling system
The one thing I am very happy about is that this do not happen while on my vacation trip with the wife and friends aboard

Thanks for any help in advance!
Paul