Ports and Waterways Safety Assessment (PAWSA) is a comprehensive and sophisticated AHP-based Delphi method in which risk analysis and risk management are handled simultaneously. PAWSA has primarily developed for maritime domain, and there is a need to extend such risk analyses to the other fields. First aim of this study is to introduce PAWSA process and to add its methodology to existing academic literature. Significance of PAWSA is exhibited and innovative suggestions for further developments are given in this study. Secondly, PAWSA method is employed for Istanbul Strait to obtain the levels of navigational risks and to measure effectiveness of counter actions. It analyses risks of navigation situations, the conditions of vessels, traffic intensity and waterway characteristics. Ultimately, it is aimed to minimize the marine incidents and increase navigational safety by introducing new counter actions. The Istanbul Strait is one of the most difficult-to-navigate and the narrowest international waterway in the world. The Istanbul Strait has a dense traffic because of its geographical and strategic location. According to annual statistics, traffic density is two times more than the Suez Canal and three times more than the Panama Canal. Besides the heavy local traffic, the Strait is used by approximately 50.000 international vessels with a total gross tonnage of 600 million. 15 million people live in Istanbul and 300.000 people are transported daily from Asia to Europe using Istanbul Strait. A comprehensive risk analysis by a convenient method for the Istanbul Strait is therefore required for safe maritime transportation.