Shipmanager Wallem has escaped any penalty after one of its executives told a female cadet it did not employ "girls" on its clients' ships.
A UK employment appeal tribunal found that UK law does not protect seafarers from sex discrimination if they work overseas on foreign-flagged vessels.
It ruled the original 2018 tribunal was correct to find that it had no power to decide a claim by cadet Sophia Walker against the Hong Kong company and its former employee Brian Phipps.