Two stories, Her Name Was Rio and The Honourable Member, need a little knowledge of how the accepted rules of salvage work here and now. This is an exerpt from Wikipedia.
Marine salvage is the process of recovering a ship, its cargo, or other property after a shipwreck. Salvage encompasses towing, refloating a sunken or grounded vessel, or patching or repairing a ship. Today the protection of the environment from cargoes such as oil or other contaminants is often considered a high priority.
“Salvors” are seamen and engineers who carry out salvage to vessels that are not owned by themselves, and who are not members of the vessel’s original crew. When salvaging large ships, they may use cranes, floating dry docks and divers to lift and repair ships for short journeys to safety towed by a tugboat. The aim of the salvage may be to repair the vessel at a harbour or dry dock, or to clear a channel for navigation. Another reason for salvage may be to prevent pollution or damage to the marine environment. Alternatively the vessel or valuable parts of the vessel or its cargo may be recovered for its resale value, or for scrap.
In pure salvage (also called “merit salvage”), there is no contract between the owner of the goods and the salvor. The relationship is one which is implied by law. The salvor of property under pure salvage must bring his claim for salvage in a court which has jurisdiction, and this will award salvage based upon the “merit” of the service and the value of the salvaged property.
Pure salvage claims are divided into “high-order” and “low-order” salvage. In high-order salvage, the salvor exposes himself and his crew to the risk of injury and loss or damage to his equipment in order to salvage the property that is in peril. Examples of high-order salvage are boarding a sinking ship in heavy weather, boarding a ship which is on fire, raising a ship, plane, or other sunken property, or towing a ship which is in the surf away from the shore. Low-order salvage occurs where the salvor is exposed to little or no personal risk. Examples of low-order salvage include towing another vessel in calm seas, supplying a vessel with fuel, or pulling a vessel off a sand bar. Salvors performing high order salvage receive substantially greater salvage award than those performing low order salvage.
In order for a claim to be awarded three requirements must be met: The property must be in peril, the services must be rendered voluntarily (no duty to act), and finally the salvage must be successful in whole or in part.
There are several factors that would be considered by a court in establishing the amount of the salvor’s award. Some of these include the difficulty of the operation, the risk involved to the salvor, the value of the property saved, the degree of danger to which the property was exposed, and the potential environmental impacts. It would be a rare case in which the salvage award would be greater than 50 percent of the value of the property salvaged. More commonly, salvage awards amount to 10 percent to 25 percent of the value of the property.
Private boat owners, to protect themselves from salvage laws in the event of a rescue, would be wise to clarify with their rescuer if the operation is to be considered salvage, or simply assistance towing. If this is not done, the boat owner may be shocked to discover that the rescuer may be eligible for a substantial salvage award, and a lien may be placed on the vessel if it is not paid.
Salvage law has as a basis that a salvor should be rewarded for risking his life and property to rescue the property of another from peril. Salvage law is in some ways similar to the wartime law of prize, the capture, condemnation and sale of a vessel and its cargo as a spoil of war, insofar as both compensate the salvor/captors for risking life and property. The two areas of law may dovetail. For instance, a vessel taken as a prize, then recaptured by friendly forces on its way to the prize adjudication, is not deemed a prize of the rescuers (title merely reverts to the original owner). But the rescuing vessel is entitled to a claim for salvage. Likewise a vessel found badly damaged, abandoned and adrift after enemy fire disabled her does not become a prize of a rescuing friendly vessel, but the rescuers may claim salvage.
A vessel is considered in peril if it is in danger or could become in danger. Examples of a vessel in peril are when it is aground or in danger of going aground. Prior to a salvage attempt the salvor receives permission from the owner or the master to assist the vessel. If the vessel is abandoned no permission is needed.
What the Serenity crew are doing, and what Mal later wants to make legal, is not exactly what salvage laws cover.