Abstract Ships trade in a complex and high-risk operating environment; hence very many shipping casualties still occur at sea as well as waters connected therewith. Any accident, whatever in nature, is every seafarer's nightmare and comes under the fierce scrutiny of the public. It may take different shapes - i.e from a single operational mishap to a possible major regional catastrophe. Should it occur in a channel or a strait, where the shipping traffic is dense, the sea-room is relatively insufficient and depth of water is rather restricted, serious risks are likely to be faced. Several causes may give rise to a shipping casualty. In broad terms these are: inter alia, naturai conditions, technical failures, route conditions, ship-related factors and human errors. The Strait of Istanbul , the Bosphorus, is roughly a "S-shaped" narrow channel and links the Black Sea to the Sea of Marmara. It is thus the integral part of the Turkish Straits; namely the Dardanelles,the Sea of Marmara and the Bosphorus, the whole area being known as the Turkish Straits Region (TSR), which constitute one of the major and busiest seaways. Geogaphical conditions and navigational constraints of the Strait, i.e. narrowness, deep and steep structure which grants poor visibility at nights for ships passing through, and day-ta-day changing currents together with bad weather conditions, are the main parameters contributing to marine casualties in the Bosphorus. The Strait has faced 454 marine casualties of different types in 1953-2002 period, accounting 24 percent for the "left-side up scheme", 60 percent for the "right-side up scheme and the remaining 16 percent for the "traffic separation schemes" respectively. The Turkish Government adopted the by-law, so-called "Maritime Traffic Schemes in the Turkish Straits Region", currently in use in 1994 and revised further in 1998, to enhance safety of navigation in the Strait as a life saving measure, Hence, with full implementation of the By-law, shipping casualties in the Bosphorus have been drastically reduced.