Dark-class fast patrol boats
... that the diesel exhausts from the Royal Navy's Dark-class fast patrol boats caused the ships to become so dirty that they had to paint the hulls black?
... that the diesel exhausts from the Royal Navy's <b id="mwDFg"><a class="mw-redirect" href="./Dark_class_fast_patrol_boat" id="mwDFk" rel="mw:WikiLink" title="Dark class fast patrol boat">Dark-class fast patrol boats</a></b> caused the ships to become so dirty that they had to paint the hulls black?