West Australian shipbuilder Austal has secured a multi-million-dollar contract to construct the next batch of Customs and Border Protection patrol boats.

Prime Minister Julia Gillard made the announcement today while touring the company's base in Henderson, south of Perth.

The $330 million contract will see eight Cape Class boats replace an ageing fleet.

Ms Gillard says the investment will boost the Western Australian economy.

"This investment will support 500 direct jobs and indirectly will support around 1,000 more," she said.