Boat diesel mechanic

I have a 37 foot sailboat with the 4-108 Perkins diesel inboard engine that may have to be partially rebuilt? The engine took on water, I flushed and changed all fluids. The engine started and ran but evidently I didn't run it long enough to completely eliminate interior moisture! Now I am unable to start it. The piston rings appear to be stuck. I've been adding a penetrating oil and turning it over occasionally. I would like to hire someone with experience to attempt to restart and if necessary rebuild on location.