Authority for the doctrine of deviation can be traced back at least to as early as 1800 in sea carriage,1 and 1828 in carriage by land.2 Its ambit extended to any departure from the agreed or customary contract route by the carrier without due justification.3 The doctrine, subsequently developed by analogous reasoning, eventually extended to all situations of bailment. The effect of unjustified deviation would be to deprive the carrier or bailee of the protecting terms of the contract such as might normally limit or exclude his liability. Deviation would thus prevent a shipowner relying upon exemption clauses contained in the bill of lading.4 Upon deviating the carrier was said to become an insurer of the goods; this provides us with the original rationale of the doctrine, that upon deviating from the contract voyage the cargo insurance cover became void. This was prior to the modern deviation or “held covered” clauses in marine insurance. A deviating carrier immediately became strictly, almost absolutely, liable for the goods being carried in the interests of the cargo owner.5 It was considered that the carrier “stepped out” of the contract losing the protection of exemption clauses therein, as such clauses were only intended to apply while the carrier was performing the contract: upon deviation the contract was no longer being pursued.6

Examples of the doctrine include bailees storing goods in other than the agreed place7 or sub-contracting the goods without permission.8 A railway company dispatching a consignment of theatrical props to the wrong destination9 or the sending of goods by ordinary coach when the mail coach had been agreed on.10 Wrongfully retaining the bailed goods has likewise been held to be an act of deviation.11 Further authorities have made it an act of deviation to leave the goods unattended for long