Marine Insurance Act, 1963
86. Implied obligation varied by agreement or usage
(1) Where any right, duty, or liability would arise under a contract of marine insurance by implication of law, it may be negative or varied by express agreement, or by usage, if the usage be such as to bind both parties to the contract.
(2) The provisions of this section extend to any right, duty, or liability declared by this Act which may be lawfully modified by agreement.