Bubblerat,
Greenpeace converted the Rainbow Warrior into a motor/sailing vessel by constructing three masts on the hull of a North Sea fishing trawler formerly called the Grampian Fame.

It is an ocean-going vessel equipped with the latest in electronic navigation, sailing and communications equipment.

If it was only able to sail, it would not be able to effectivly interfere with whaling operations or much else of its valuable work.