The issues with the patrol boats were made public on the same day Austal announced it had been awarded a contract with a potential value of $US3.3 billion for the detail design and construction of up to 11 offshore patrol cutters for the US Coast Guard.

Eastern Shipbuilding Group had been building the cutters but delays prompted the Coast Guard to re-tender the project. Eastern responded by filing a protest with the Government Accountability Office in the US.

Mr Gregg said there would be more certainty around the Coast Guard contract in October when US authorities ruled on that protest, but he remained confident because Austal and the Coast Guard had done everything by the book.

Austal, whose biggest shareholder is Andrew Forrest with 15.4 per cent, reported full-year net profit after tax of $79.6 million, down from $81.1 million last year, while revenue slumped 9 per cent to $1.43 billion as the long-running Littoral Combat Ship building program for US Navy started to wind down.

The company is forecasting earnings of $100 million 2022-23, down from $120.7 million.

However, Austal is sailing into the year with an order book, inclusive of contract option agreements, of $7 billion, the largest in its history.

Mr Gregg said it was a good time for Austal to be skewed towards defence shipbuilding.

“In my mind, defence spend is driven by the threat that the countries face,” he said. “And while we see agitation with China, concern around what Russia did in Ukraine … it is probably a good time to be in defence and, more specifically, shipbuilding.”