; or (C) who otherwise constitutes a threat to the safety of the vessel; (6) ensure and certify to the Secretary that the vessel is in compliance with section 3304 and chapter 35, to the extent such section or chapter otherwise applies to the vessel; and (7) ensure that each nonoperating individual on board the vessel is employed under conditions that meet or exceed the minimum international standards of all applicable international labor conventions to which the United States is a party, including all of the merchant seamen protection and relief provided under United States law. (b) Work restrictions A nonoperating individual on board a vessel to which subsection (a) applies may not perform on board the vessel— (1) watchstanding, automated engine room duty watch, navigational, or personnel safety functions; (2) cargo handling functions, including any activity relating to the loading or unloading of cargo, the operation of cargo-related equipment (whether or not integral to the vessel), and the handling of mooring lines on the dock when the vessel is made fast or let go; (3) vessel maintenance, including any repairs that can be performed by the vessel’s crew or a riding gang member