We were tied up at the end of the customs/pumpout dock pumping out when I saw a 35ish foot Beneteau approach the dock from the opposite direction, downwind and downcurrent. The skipper reversed strongly but late and the boat sideswiped the dock hard. Then POW! a fender exploded, separated from its pennant, not to be seen again. I got ashore quick and grabbed their stern line, judging that I needed to use body strength to slow it down before I could safely snub on the next cleat forward. It came to rest a comfortable distance from our boat. Meanwhile, the skipper had jumped ashore to secure the bow line. That was really not necessary. He would have done better to stay aboard and apply a bit more reverse. His Admiral was not a participant. I suspect these folks were relatively new at it.