Electronic Chart Display and Information System (ECDIS) offers navigators more functions and information than a paper chart. ECDIS manufacturers have applied all navigational operations to ECDISs that can be performed using paper charts. The system is designed to support the navigators in a way that does not look like a paper chart with these functions. However, the frequency of using ECDIS functions may vary due to different age groups, fields of study, competencies, etc. ECDIS functions, suitability and usage frequency are subjected in this study. Ship masters and deck officers (including deck cadets) apply the "ECDIS Functions Usage Frequency Questionnaire" for aiming to understand how they use these functions via a web-based survey. In addition, how often the navigators use the specified ECDIS functions were assessed. A total of 55 different ECDIS functions and their usage frequency were analyzed by using IBM SPSS v.25 by questioning 83 active navigators. Moreover, one of the goals of this study is to understand the awareness of correct usage. According to various age, qualification groups and ship types, the variety of applications of ECDIS's international standards determined by the International Maritime Organization and the frequency of usage and its functions were tested. As a result of this survey study, the frequency of usage was correlated by associating the professional competencies of the navigators. The five most basic and frequently used functions were also determined and interpreted.