Dick, my understanding is that earthquake-induced tsunami waves are usually unnoticeable in the open ocean. They spread out and are very small until a rising seafloor concentrates their power. I don't know the conditions around Bouvet, but if the ship was in deep water and not dragged into the island this is unlikely to have been an issue. The waves could have been a disaster if anyone was on the beach, but I believe everybody was planning to stay on high ground. As for being on land, 6.5 is quite serious, though hopefully having tents rather than houses would minimize the damage. That is not something anyone would want to test, though.