Closed cooling is always good, however once the boat has been run in salt, its a bit late to add it.
the water everywhere is a concern along with the water in the oil and on the plugs
how did you do the winterization, specifically, and step by step. The required process is to remove the drain plugs, drain everything, disconnect the supply hose to the raw water pump and drain that. pull the impeller and place impeller in a plastic bag with the plugs removed from the motor. zip tie the plastic bag to the steering wheel (so they dont get lost). change all fluids and filters
come spring, reinstall the impeller, or install new impeller, reinstall drain plugs and go boating.
I suspect a cracked block from improper winterization, or simply the plugs were left out and not installed in spring.
with the boat on the trailer, and running the engine on the muffs, where specifically is the water coming from?
