The newest ship in the US-flag fleet is the centre of New York-based Liberty Maritime’s latest conflict with one of the country’s largest seafarer ­unions.

The episode underscores the challenges confronting all sides of the US-flag maritime industry, in which unionised seafarers face diminishing benefits in an effort to remain employed.

For its part, Liberty Maritime is seeing less chartering from the US military, forcing it to seek out more commercial work.