We had the same experience, but it was shrimp that make a clicking noise
that transmits through the water. We had a totally clean bottom and still
got the noise.

Doug
s/v Callista

"MLapla4120" wrote in message
...
Hi,
Recently posted, asking for advice about how to get rid of a rat on my
boat.
Guess what, the noise was from crabs on the hull, munching on the great
eats for them on the hull. I had the hull cleaned and everything stopped.
I was wondering about the noise. The fact is without droppings, I should
have
known.