Pull the risers first. Look down inside the manifolds for water or deposits where water has been running down.
I'm not sure why it happened so far apart. Were you idling a for long time both times????

what does the valvetrain look like? If there is no condensation there I doubt thats the problem .....m

Pull your spark plugs out and disconnect your coil, and have someone turn the motor over while you watch to see if any water is exiting the cylinders. Often you will see water comming out of the cylinder that is effected. Also attempt to read the spark plugs. Typically they should be a light brown . If you have water in a cylinder it should be quite evident. Don't turn it over too much keep in mind you are dumping raw fuel out of the cylinders and you do not want a fire.

As stated if there is a problem cylinder that plug will be very clean ...also when checking the plugs you can usually see beads of water on the plug (look closely) from the bad cylinder .....m

I will check my plugs tomorrow and post. i would have had it ideling for about 10 min just to warm it up to move it to the crane. I dont think that is too long is it?

As for the valve train i have white/tan oil water foam under my oil cap and coming out my crankcase vent hoses intyo my flame arrestor. This has been there for as long as i have owned the baot 2 years, i was told that it condensation and isn't a big deal for a 1987 boat. Is that true?

thanks,

Did you find out the problem? I have same issue.

Exhaust manifolds

A reputable marina can pressure test the cooling system. From that the leak can be pinpointed. I would do that before wasting time and playing the guessing game.

I just found my leak, it was intake gaskets. They were pouring!!

ted you missed your calling