In addition to the express clauses agreed by the parties, every contract of affreightment is
negotiated against a background of custom and commercial usage from which a series of
obligations are implied which are automatically incorporated into the contract in the absence
of agreement to the contrary. Since such obligations are derived from a common source in
the law merchant, a similar result follows at common law irrespective of whether the terms
of the contract are enshrined in a charterparty or evidenced by a bill of lading. There is, however,
one important proviso. In contracts of carriage which are governed by the Hague or
Hague/Visby Rules the scope and application of some of these implied obligations have been
modified while the ability of the parties to exclude their operation by mutual agreement has
been considerably restricted. In the following pages each of these implied obligations will
be considered separately and a final section will be devoted to the effect of frustration on a
contract of affreightment.