A number of measures could and should be taken to avoid discharges of oil from shipping (oil tankers and other vessels) and from platforms for offshore oil extraction. Measures to reduce the risk of accidents involving tankers, and measures to reduce operational discharges from all kinds of commercial vessels, include the following:


Requirements for double hulls or double bottoms are being introduced. In 1992, the MARPOL Convention was amended to make it mandatory for tankers of 5,000 dwt and more (ships ordered after 6 July 1993) to be fitted with double hulls, or an alternative design approved by IMO (Regulation 13F in Annex I of MARPOL 73/78).  The requirement for double hulls that applies to new tankers has also been applied to existing ships under a programme that began in 1995 (Regulation 13G in Annex I of MARPOL 73/78).  All tankers have to be converted (or taken out of service) when they reach a certain age (up to 30 years old). This measure is being phased in over a number of years because shipyard capacity is limited and it would not be possible to convert all single hulled tankers to double hulls without causing immense disruption to world trade and industry. There are also concerns about building vessels too fast and compromising design standards. ••• An additional possible measure is to limit the size of individual tanks within ships so that spills that occur at least are smaller.

Single hull is a ship construction term. In tankers with single hulls, oil in the cargo tanks is separated from the seawater only by a bottom and a side plate. Should this plate be damaged as a result of a collision or stranding, the contents of the cargo tanks risks spilling into the sea. An effective way of avoiding the risk is to surround the cargo tanks with a second internal plate which is at a sufficient distance from the external plate (generally 1.5-2 metres). This design, known as a double hull, safeguards cargo tanks from damage and thus reduces the risk of oil pollution. The double hull construction incorporates both double bottoms and double sides. An alternative solution is to have ships with double sides (double hull along the sides of the ship, an added side-shell plating structure fitted within the ship while the bottom of the ship has a single plate, a single bottom. This means that the cargo tanks are separated from the seawater only by a bottom plate. Double bottom, on the other hand, is a ship construction term referring to two separate but continuous and water-tight plating structures along some length and width of a ship's bottom.

The U.S. has already banned single hull-vessels in their waters and has stronger liability legislation in their Oil Polllution Act.

Shortly after the Erika accident, the EU Commission presented a number of proposals to help prevent such accidents occurring again. One measure was a proposed Regulation on the phasing out of single-hull oil tankers. This Regulation was adopted on 20 February 2002, and applies from 1 September 2002. This measure was also agreed at the international level when the IMO adopted a revision of its Regulation 13G of Annex I to MARPOL 73/78 in April 2001. In 2002, after the Prestige accident, it became clear that the international and previously agreed EU schemes were not sufficiently ambitious. The Commission announced a number of measures to minimise the risk of future accidents involving ships such as Erika and Prestige. The Transport Council in 2002, furthermore called for an acceleration of the calendar for phasing-out of single-hull tankers, for applying the Condition Assessment Scheme from 15 years of age, as well as the conclusion of administrative agreements by Member States in view of refusing single hull oil tankers carrying the heaviest grades of oil into their ports, terminals and anchorage areas.


Ship owners must ensure a high standard of maintenance. No matter how well a ship is designed, built and equipped — unless it is properly maintained, it will sooner or later become a maritime safety risk. The responsibility for regular and good maintenance always rests with the ship owner. It is also worth remembering that also double-hulls have their own inherent problems. Many predict that in a few years time there will be massive oil spills from double-hull tankers as the maintenance of a double-hull is more difficult than a single-hull, and there is also a problem with gas build up between the two hulls. This will make regular inspections of the vessels even more important.


Furthermore, it is the responsibility of the ship owner to recruite crews that are competent and experienced. The crews should also be continuously trained. Many accidents are due to the human factor, and unless the crew members do their job right it does not really matter how well equipped the ship is.


Better navigational equipment — for example, electronic charting — is needed. All ships must have radar systems to improve navigation (large ships must have two systems that operate independently). In busy shipping corridors, traffic separation schemes and vessel traffic control are required to reduce the risk of a collision. In some areas, mandatory pilotage should be introduced.

High-standard fire-fighting equipment must be available and strict fire safety regulations apply on board.

Monitoring and control equipment should be installed on ships so that discharged oil-water mixtures can be traced back to the ship that was carrying the oil.


The purposes of surveillance is to function as a deterrent from discharging ship-generated wastes altogether, as a means of detection of discharges already made, and as a tool to combat, as effectively as possible the spills that have been detected. Airborne surveillance which increases the ship's risk of being caught in the process of making illegal discharges can be an effective measure to prevent discharges and thus reduce marine pollution from shipping. In the future, airborne surveillance on a regional scale should be introduced in more areas, particularly in the MARPOL Special Areas (as is already the case in the Northeast Atlantic and the Baltic Sea).


Frequent inspection of ships, particularly older ones, are imperative. Since 1995 all tankers and bulk carriers aged five years and over have been subject to a specially enhanced inspection programme which is intended to ensure that any deficiencies — such as corrosion or wear and tear resulting from age or neglect — are detected. Guidelines on enhanced surveys on tankers and bulk carriers are contained in Assembly resolution A. 744 (18), adopted in November 1993.  Inspections are coordinated on a regional scale through Memoranda of Understanding on Port State Control (MoUs).


Better facilities are needed in ports for ships to leave their oily liquid waste and solid oily waste. In MARPOL Special Areas, such port reception facilities are required. However, in order to further reduce marine oil pollution from shipping such facilities should be made universally available in all ports where oil and oily wastes are handled. These facilities should, preferably, be made available at no extra cost, the so-called no special fee system presently in use in the Baltic Sea region.


Finally, the responsibility for upholding safe sea transports of oil products rests also with the cargo owners and the end users, the consumers of the products. Cargo owners should not use sub-standard vessels, but should be prepared to pay for high-quality shipping. Ultimately, the additional costs for choosing to charter safe and well maintained ships will (marginally) affect the price of the products, but it is a small price to pay as a means to prevent as far as possible the pollution of the coastal and marine environment by oils.