few years back and a bunch of them came by me. I was on auto pilot and down below making myself a sandwich when they approached from the stern. There were three groups of four in each group. The middle group split and 2 went on each side of me. My dinghy hangs on davits and blocks my view towards the stern unless I stand up so I didn't see them from down below until they passed me. It was so loud that I couldn't figure out where the sound was coming from and for a few seconds actually thought it was my engine going south because it was such a low rumble.