1640s, "payment for saving a ship from wreck or capture," from French salvage (15c.), from Old French salver "to save" (see save (v.)). The general sense of "the saving of property from danger" is attested from 1878. Meaning "recycling of waste material" is from 1918, from the British effort in World War I.
1889, from salvage (n.). Related: Salvaged; salvaging.
To steal; loot; liberate (WWI Army)
in maritime law, the rescue of a ship or its cargo on navigable waters from a peril that, except for the rescuer's assistance, would have led to the loss or destruction of the property. Under some jurisdictions, aircraft may also be salved. Except for salvage performed under contract, the rescuer-known as the salvor-must act voluntarily without being under any legal duty to do so, apart from the general duty to give assistance to those in peril at sea or to stand by after a collision. So long as the owner or his agent remains on the ship, unwanted offers of salvage may be refused. A derelict-a vessel found entirely deserted or abandoned without hope or intention of recovery-is, however, fair game for anyone who comes across it. Typical acts of salvage include releasing ships that have run aground or on reefs, raising sunken ships (or their cargo), putting out fires, and so on.