4.0 Background and Premise

Since the case of Davis v. Garrett,1 it has been established that, in the absence of any contractual provision giving liberty to deviate, the law implies ‘a duty in the owner of a vessel, whether a general ship or hired for the special purpose of the voyage, to proceed without unnecessary deviation in the usual and customary course’. The owner of a vessel implicitly agrees that his vessel will not deviate from the contract voyage while conducting its obligations under the contract of carriage. Deviation, therefore, has been defined as an intentional and unreasonable change in the contracted geographic route of a voyage.2 To determine if such a deviation has occurred, it is necessary to first determine the precise route envisioned by the contract of carriage. A few standard charter forms make express provisions for the route to be followed;3 however, in the absence of such provisions, the legitimate route is presumed to be the direct geographical route between the ports of loading and discharge. This presumption may be rebutted, however, if the shipowner provides evidence of the customary route in the trade or even the route previously followed by the particular shipping line in question.4