4. Exceptions from liability under section 3
Feedback & supportThe owner of a ship from which oil has been discharged or has escaped shall not incur any liability under section 3 if he proves that the discharge or escape —
owner
“owner”, in relation to a ship, means the person registered as the owner of the ship, or, in the absence of registration, the person owning the ship, except that, in relation to a ship owned by a State which is operated by a person registered as the ship’s operator, it means the person registered as the operator;
resulted from an act of war, hostilities, civil war, insurrection or an exceptional, inevitable and irresistible natural phenomenon;
was due wholly to anything done or left undone by another person, not being an employee or agent of the owner, with intent to do damage; or
was due wholly to the negligence or wrongful act of a government or other authority in exercising its functions of maintaining lights or other navigational aids for the maintenance of which it was responsible.