Hague-Visby Rules define the concept of ship deviation, but merely specifies the types of deviation which are justifiable under the Rules. Presumably there is no intention to disturb well-established common law principles, the object of the provision being to provide extended protection for shipowners by adding deviations to save property and reasonable deviations to the existing list of deviations which are justifiable at common law.
English courts have, however, experienced some difficulty in interpreting the phrase any reasonable deviation, although it appears to be generally accepted that whether or not a deviation is reasonable is to be treated as a question of fact. In Stag Line v Foscolo, Mango & Co a vessel on a voyage from Swansea to Constantinople made a slight deviation into St Ives to land two engineers who had been taken on board for the purpose of testing her fuel-saving apparatus. On leaving St Ives, the vessel ran aground and the cargo was lost. The House of Lords held that this was not a reasonable deviation and refused to allow the shipowner to rely on the protection afforded by the Hague Rules. In an attempt to clarify the issue, Greer LJ in the Court of Appeal had said: ‘I think the words [reasonable deviation] mean a deviation whether in the interests of the ship or the cargo-owner or both, which no reasonably minded cargo-owner would raise any objection to.’ In the Lords a variety of alternative definitions was advanced, the main difference of opinion turning on the question as to whether a deviation could be reasonable if it was not in the interests of both ship and cargo.
Despite these attempts at clarification of the reasonable deviation concept, there are remarkably few reported English cases in which a carrier has successfully invoked the defence. A similar uncertainty surrounds the application of the concept in other jurisdictions and the majority of courts have tended to be strict in their interpretation of what amounts to reasonable conduct in this context. It is also interesting to note that the United States version of Art IV rule 4 of the Hague Rules includes the proviso that ‘if the deviation is for the purpose of loading or unloading cargo or passengers, it shall, prima facie, be regarded as unreasonable’.
A final point of uncertainty relates to the relationship between express liberties to deviate contained in the contract of carriage and the provisions of Art IV rule 4. If such liberties are not regarded by the courts as ‘reasonable’ within the meaning of Art IV, are they caught by Art III rule 8 which renders void any clauses which derogate from the protection offered by the Rules? The better view would appear to be that there is no conflict since the object of the liberty clause is to define the scope of the contract voyage and in such an event it is difficult to understand how a permissible ‘deviation’ can constitute a breach of contract.
In holding that an express liberty to deviate is not affected by Art IV rule 4 Hodson LJ expressed the view that ‘the object of the Rules is to define, not the scope of the contract of service, but the terms on which that service is to be performed’. (II) Dangerous cargo Article IV rule 6 defines the liability for the shipment of dangerous cargo. This specific provision in the Rules reinforces the implied term at common law that the shipper will not ship dangerous goods without the consent of the carrier. Rule 6 provides that when such goods are shipped without the knowledge or consent of the carrier, not only is he entitled to neutralize them at the expense of the shipper, and without any obligation to compensate the cargo-owner, but the shipper is also liable for any loss or damage resulting from their shipment. The latter liability will not normally arise in circumstances where the carrier consents to the shipment with full knowledge of the dangerous nature of the cargo.
Even though the carrier initially consents to the shipment of dangerous goods he may nevertheless dispose of them in like manner should they subsequently endanger either the ship or the cargo, though presumably not in this case at the expense of the shipper.