16In subsection (8) of section 9 of the [1971 c. 60.] Prevention of Oil Pollution Act 1971 (under which a harbour authority is liable to a fine not exceeding £10 for each day on which it fails to comply with a direction to provide oil reception facilities) for the word " £10" there shall be substituted the words " £500 and to a further fine not exceeding £50 ".