Unlimited displacement racing has a very long history. Quite simply, it is the category for racers who do anything to their boats in order to go fast. No limitations or restrictions, just go for maximum speed and use whatever equipment it takes!
Naturally this category has existed longer than any. The first unlimited class in Australian racing began back in the early 1900′s and consisted of any boats with engines larger than 300 cubic inches. Nowadays in this 21st century the boats have taken a quantum leap in terms of speed, manouverability, and now safety.
Unlimited boats have changed significantly since the introduction of class racing, of which the onset was after World War II when the availability of automotive V8 engines increased along with the boom in world wide car sales. Once the 6000cc (6 litre) class was introduced to suit the revolutionary 350 Chevrolet small block, any race boat with a higher engine capacity was considered unlimited.