The International Maritime Organization (IMO) states about their Convention on Salvage: “The Convention replaced a convention on the law of salvage adopted in Brussels in 1910 which incorporated the "'no cure, no pay" principle under which a salvor is only rewarded for services if the operation is successful.
Although this basic philosophy worked well in most cases, it did not take pollution into account. A salvor who prevented a major pollution incident (for example, by towing a damaged tanker away from an environmentally sensitive area) but did not manage to save the ship or the cargo got nothing. There was therefore little incentive to a salvor to undertake an operation which has only a slim chance of success.
The 1989 Convention seeks to remedy this deficiency by making provision for an enhanced salvage award taking into account the skill and efforts of the salvors in preventing or minimizing damage to the environment.”
It was adopted on April 28, 1989 and entered into force on July 14, 1996.