Section 267S of th e Principal Act is amended ;
(a) by inserting after subsection (1) the following subsection :
" (1A) Without limiting the generality of subsection (1), an Australian ship in respect of which a chemical tanker construction certificate is in force shall, for the purposes of that subsection , be taken to be damaged if the ship becomes unfit to proceed to sea without presenting an unreasonable threat of harm t o the marine environment. " ; and
(b) by omitt ing subsection s (3) and (4).