Motorship wrecks on the seabed pose a serious threat to the marine environment due to oil leaking from their fuel tanks. Such substances can penetrate the sediments and enter the water. There is a need to analyse bottom water and seabed sediment samples for the content of toxic petroleum substances. Tests were undertaken on samples collected near the site of the World War II shipwreck of the s/s “Stuttgart”. The wreck is located in the Baltic Sea, in the Gulf of Gdańsk. To answer whether toxic hydrocarbons from wrecks enter the sea environment, a fluorometric analysis was carried out based on measurements of excitation-emission ultraviolet spectra for sediments and near-seabed water. The results of these analyses indicate the presence of oil substances in the sediments and the bottom water at some sampling points close to the wreck site. Studies have shown that the applied method of the so-called fluorometric indicator allows for determining the sites of water pollution with oil substances hidden in sediments.