Guardian Australia analysis of International Whaling Commission data shows motor yachts, naval vessels and ferries come close behind.
Whales are more likely to to be hit by whale-watching boats than any other identified vessel type, data from the International Whaling Commission shows.
Whale collisions around the world have been collated by the commission in a database which runs from 1885 to 2010.
While the type of vessel is unknown in most incidents, where the boat type was identified the highest number of collisions came from whale-watching vessels. Motor yachts, naval vessels and ferries came close behind.
Paul Farrell and Nick Evershed
The Guardian Newspaper