In order to avoid danger to the ship or cargo. The master is under an obligation to exercise reasonable care and skill in ensuring the success of the joint enterprise and accordingly is entitled to deviate from the proper course in order to ensure the safety of the vessel and its cargo. Indeed, in the majority of cases, he will be under a duty to take such action. The risks may arise from natural causes such as storms, ice or fog, or they may involve political factors such as the outbreak of war or the fear of capture by hostile forces. In
either case, however, the danger must be of a reasonably permanent nature, since a master would not be justified in substituting a substantially different voyage in order to avoid a risk arising from a merely temporary obstruction such as a shortage of tugs or a neap tide.
One of the most frequently encountered examples of this type of justifiable deviation is the vessel which, for safety reasons, has to put into port for repairs to damage sustained on the voyage. Nor is it apparently material that the damage has resulted from the initial unseaworthiness of the vessel. Thus in Kish v Taylor a vessel had been chartered to load a full and complete cargo of timber at two ports in the Gulf of Mexico for carriage to western Europe. On the charterer failing to provide a full cargo, the master procured further
timber from other shippers, some of which he loaded on deck in such a way as to render the vessel unseaworthy. Heavy squalls were encountered during the voyage which caused the deck cargo to shift and endanger the safety of the vessel. Accordingly the master put
into Halifax for the necessary repairs before proceeding to Liverpool where he discharged the cargo. When the shipowner sought to exercise the contractual lien for dead freight and demurrage, the cargo owner contended that the right to rely on the lien had been forfeited as the result of what was alleged to be an unjustifiable deviation to Halifax. The House of Lords rejected this argument and held the deviation to be justified even though it resulted from initial unseaworthiness. In their view justification was to be sought in the existence of a danger and not in its cause. It would appear that a deviation may be justified although the risk to be avoided affects only the ship and not the cargo. On the other hand, in the reverse situation, the position is far from clear. There is authority for suggesting that where continuation of the voyage would result in substantial damage to the cargo, the master might be under a duty to
deviate to protect the interests of the cargo owners, but it is doubtful whether such an obligation arises where the apprehended damage is slight or only affects part of the cargo. While the master is expected to take into account the interests of both ship and cargo, ‘I am not prepared to hold that the instant it becomes clear that by going on some mischief will be done to some portion of the cargo that it becomes the duty of the captain to go back, and perhaps put all concerned to a very enormous expense . . .’ Presumably the decision as to whether a deviation is justified in such circumstances will depend upon a comparison between the gravity of the danger and the inconvenience and expense of taking avoiding action.