The law of salvage is a concept in maritime law which states that a person who recovers another person's ship or cargo after peril or loss at sea is entitled to a reward commensurate with the value of the property so saved. The concept has its origins in antiquity, with the basis that a person would be putting himself and his own vessel at risk to recover another and thus should be appropriately rewarded. A related consideration was widespread piracy; a vessel in peril could very well be left for pirates if the owner did not generously reward a potential honest salvor. Salvage law has been recognized for centuries in such documents as the edicts of Rhodes and the Roman Digest of Justinian. It is still a nearly universally recognized right, though conditions for awards of salvage vary from country to country.
The right to be rewarded for salvage at sea under common law is based both on equitable principles and public policy and is not contractual in origin. Historically, salvage is a right in law, when a person, acting as a volunteer (that is, without any pre-existing contractual or other legal duty so to act) preserves or contributes so to preserving at sea any vessel, cargo, freight, or other recognized subject of salvage from danger. This is the typical case of salvage and is distinct from Prize law, which is the rescuing of property from the enemy at a time of war, for which a reward is made by the Court of Admiralty sitting as a Prize Court.
The law seeks to do what is fair to both the property owners and the salvors. The right to salvage may not necessarily arise out of an actual contract but is a legal liability arising out of the fact that property has been recovered. The property owner who had benefit of the salvor's efforts must make remuneration, regardless of whether he had formed a contract or not. The assumption here is that when faced with the loss of his vessel and cargo, a reasonable prudent owner would have accepted salvage terms offered, even if time did not permit such negotiations.
Although salvage laws vary from one country to another, generally there are conditions that must be met to allow a claim of salvage. The article under salvage must be fit into certain recognized categories. The vessel must be in peril, which is defined broadly. The person rendering aid (the "salvor") must be acting voluntarily and under no pre-existing contract. Finally, the salvor must be successful in his efforts, though payment for partial success can be granted in certain circumstances.