Implied obligation related to deviation. “Deviation” is customarily considered to be an unreasonable departure from the usual route for a contractual voyage and a return to that route.
This causes the word to be restricted to a geographical sense. However, the word can also refer to a departure from the expected and contractual manner of performing the contract. It can be applied generally to performance so that a carrier who deviates from an agreed voyage steps out of the contract and “. . .
clauses in the contract (such as exceptions or limitations clauses) which are designed to apply to the contracted voyage are held to have no application to the deviating voyage”. (Suisse Atlantique v.
Rotterdamsche Kolen Centrale, 1966) Another statement by an eminent judge in an English court may help to appreciate the effect of deviation and that it does not have to be restricted to geographical deviation. It was said in Gibaud v.
Great Eastern Railway Company, 1921, that:
“The principle is well known . . . that if you undertake to do a thing in a certain way, or to keep a thing in a certain place, with certain conditions protecting it, and have broken the contract by not
doing the thing contracted for in the way contracted for, or not keeping the article in the place in which you have contracted to keep it, you cannot rely on the conditions which were only intended
to protect you if you carried out the contract in the way in which you had contracted to do it.”
If cargo is carried on deck when it is not intended by the parties to the contract of carriage that the cargo should be so carried, this can perhaps also be considered to be deviation (or, as it is sometimes
called in the United States, “quasi-deviation”) from the contracted performance of the contract and may prevent a carrier from relying on exceptions or limitation clauses in the contract. (See also Breach of contract, above.)
Returning to geographical deviation, this can be justified in the common law only in restricted circumstances. The chief circumstance is that the vessel deviates in order to save life or to go to the aid
of persons in distress (grave and imminent danger) at sea: An attempt to save life would be justifiable even if it is unsuccessful or becomes unnecessary. A deviation to avoid danger to the vessel or the
cargo on board is also justifiable, even if the danger to the vessel or cargo results from initial unseaworthiness. Deviating to save or attempt to save property is not justified. In the Hague and
Hague-Visby Rules geographical deviation is permitted for saving or attempting to save both life and property but the United States Carriage of Goods by Sea Act 1936, which implements the Hague
Rules, states that if deviation is to load or unload cargo or passengers it is normally regarded as unreasonable. Saving or attempting to save life is reasonable. This question of reasonableness is crucial to deviation being justified.
In Stag Line v. Foscolo, Mango & Co., 1932, the House of Lords in the U.K. decided that a deviation to land engineers who were on board for adjusting and testing the ship’s machinery was not
reasonable because this benefited only the shipowner. It was convenient to deviate to disembark the engineers at an intermediate port. “Reasonable” requires a consideration of the interests of all the
parties to a contractual adventure despite the bills of lading containing clauses which give the carrier (or shipowner) the liberty to “cdall at any ports in any order, for bunkering or other purposes; all as
part of the contract voyage”.
It may be reasonable for a vessel to call into a safe and convenient port for discharging cargo if the contractual destination is closed by strikes and the voyage would be unacceptably prolonged,
especially if perishables are among the cargo on board. If the master decides to follow a course that may be considered a deviation this would be reasonable if his decision is correctly made but perhaps
unreasonable if he makes an error in judgment.