So Thursday night I slept on a mono for the first time.

It was pretty still most of the night as we were in refuge bay. But in the middle of the night there came this thumping sound on the front of the hull. It wasn't a line as I had sorted those out before bunking down. So I am pretty sure it was the mooring apparatus banging on the bow. On my cat it's not something I've heard before. It was pretty loud and would persist for 3 minutes at a time, irregular intervals.

In the morning a breeze had returned and the banging could not be replicated.

Is this common on monos? Am I wrong, is it something else? What are the simple home remedies?