Yes, but enforcement of a national law that does not implement a “relevant instrument” (i. e. a convention or code containing port State control provisions) would be outside the scope of the port State control inspection. For example, an MCA surveyor carrying out a port State control inspection of a non-UK ship in a UK port, and believing the master to be drunk, has powers to enforce the alcohol-related provisions of Part 4 of the Railways and Transport Safety Act 2003, although this UK legislation is not a “relevant instrument” listed in the Paris MoU.
