By applying the research method of comparative analysis, this paper compares provisions of the Ordinance on Safety of Maritime Transport in Internal Waters and Territorial Sea of the Republic of Croatia and on the Manner and Conditions of Vessel Traffic Management and Information, inclusive of Collision Avoidance Rules given in its second part, with Collision Avoidance Rules 1996. The authors critically discuss the disparities between the Rules and the Ordinance. Most of the recent rules represent essential elements of navigational safety and any discrepancies in that area are unacceptable. The consistency in prescribing all issues in the area of avoidance of collision at sea is seen in the International Regulations for Preventing Collisions at Sea, 1972 (COLREGs), as the basic and comprehensive rules for avoiding collision at sea. COLREGs are an example of a thorough analysis of all rules and generally of all subjects the rules apply to. The aim of this comparative analysis is a thorough examination of inconsistencies and disparities of specific articles, i.e. the omission of essential and important parts. The evaluation and awareness of the need to observe international rules and to incorporate them into existing legal and legislative acts of the Republic of Croatia without any discrepancies are the foundation and essence of law.