A US appeals court has ruled that crew members cannot use a key US law to sue their employers for the impacts of stress in their shipboard work.

The decision by the 11th Circuit Court of Appeals in Atlanta overturns a judgment against a crewman for Maersk Line Limited (MLL), the US-flag containership division of Danish giant AP Moller-Maersk.

Former chief mate William Skye won a $2.36m