For the purposes of this Division an activity is carried on in an
"environmentally unsatisfactory manner" if:
(a) it is carried on in contravention of, or in a manner that is likely to lead to a contravention of, this Act or the regulations or an exemption given under this Act or the regulations, or
(b) it causes, or is likely to cause, a marine pollution incident, or
(c) it is not carried on by such practicable means as may be necessary to prevent, control or minimise a marine pollution incident.