Section 4

resulted from an act of war, hostilities, civil war, insurrection or a natural phenomenon of an exceptional, inevitable and irresistible character;

was wholly caused by an act or omission of a third party, which act or omission was done with intent to cause damage;

or

was wholly caused by the negligence or wrongful act of a government or other authority responsible for the maintenance of lights or other navigational aids in the exercise of that function.

Where the owner of a ship from which oil or bunker oil has been discharged or has escaped proves that the pollution damage resulted wholly or partially either from an act or omission done with intent to cause damage by the person who suffered the damage or from the negligence of that person, the owner may be exonerated wholly or partially from his liability to such person.

Restriction of liability for oil pollution damage under section 3