The type of evidence listed in this chapter can be provided by the various Contracting Parties. A cross in the box indicates what is feasible. The ability of a Contracting Party to provide the evidence in a specific case depends, naturally, on the circumstances. For instance aerial photography may not be possible due to bad weather.

For the supply of evidence each party has to decide the way they request the evidence to suit the requirements of their own jurisdiction. The requested party has to decide in what legal way they can provide the evidence.

For an efficient procurement of evidence it is advisable that direct and rapid communication be established between the parties concerned.

(1) Mediterranean Sea only
(2) Trial period

The following definitions have been used in Table 4:

Statement: a statement contains the information collected when observing the MARPOL 73/78 violations, which can take the following form according to national law:

• witness statement: a report from a person of the general public with regard to a discharge or pollution;

• official statement: an official report (procès-verbal) written and signed by an accredited officer (observer or policeman) or the statement in writing taken by an accredited officer from the witness statement.

Photographs: taken with a photographic camera or taken by special cameras with annotation (date, time, and position of the observation etc.).

SLAR (Side Looking Airborne Radar): instrument capable of detecting possible surface pollution, based on the difference between the waves suppressed by a slick and the normal waves of the surrounding waters.

Data annotation: a line of data presenting e.g. date, time, position heading superimposed on any imagery (data annotation can be obtained from navigation systems and integrated into sensors).

IR (Infra Red sensor): a sensor which provides a picture of the relative temperature differences which also indicates thicker and thinner parts of the oil slick (short-range).

UV (Ultra Violet scanner): a scanner which provides a picture of the total spill area, but only during daylight (short-range).

FLIR (Forward Looking Infra Red camera): similar to IR-sensor but with a different angle of view.

Positioning system: a system used to obtain the exact position of the observing platform. It includes Decca, GPS or other navigation systems.

Oil sample analyses by GC/MS: Gas Chromatography / Mass Spectrometry is a technique that can give a detailed spectrum of the analysed oil, i.e. its "finger print".

Darkness identification: identification of a ship's name in darkness by electronic means or by searchlight.

Satellite: satellites equipped with SAR (radar) can at regular intervals (depending on the orbits) provide information on possible discharges. The system should be considered as a limited tool complementing aerial surveillance.

Use of colour code: the colour of the oil spill depends on the layer thickness, and/or the type of oil. With the colour code it is sometimes possible to estimate the amount of spilled oil.

Radio recording: the conversation with the suspected violator recorded on tape recorder or video recorder.

Port inspection reports: a report from the Port State Inspector with copies of all relevant documents. On request, the Port State Officer can take oil samples to be analysed at a later stage.

Computer modelling: A digital calculation model can be used to backtrack from the position of a detected oil spill, with the objective of finding the original position of the discharge. The same model can also predict the drift of the slick.