Update: A mechanic came and in draining the oil found a lot of fresh
water,before the oil started draining. He pulled the plug on the vetus
muffler and it seemed full, in fact he could hear water gurgling in the engine
to muffler hose.
Apparently the muffler failed.
What's surprising about this is it an fine the last time
just before we were hauled out. Now it has water in the engine. All
the exhaust hoses look fine, no evidence of excessive heat.
The mechanics only real theory is that the muffler failed.
The other was that someone purposefully stuck a hose into the exhaust
from the outside and forced water into the engine.
They plan on filling the engine oil reservoir with diesel
fuel overnight, and then turning the engine by hand to check for water lock.
He noted the only way for the water to get into the oil was through the
cylinders and rings. They're going to replace the muffler as well since
it had to fail for this to happen. Apparently there's not much else to be
done.