Utilization of data in quantitative accident modeling is the main concern of this report. Various data sources exist in the maritime field on a global level, but the primary interest in this report are the data sources that cover the Gulf of Finland. Other databases are included for comparison purposes or when Finland does not maintain a similar database. Special attention is given to collision and grounding accidents, and to data useful in analyzing human and organizational factors. The analyzed data sources are divided into three categories: general ship traffic data, accident data, and incident data. The sources are analyzed considering following: (1) What type of data is collected and stored; (2) What is the quantity and the quality of the data; (3) Is data available to researchers and/or public; (4) Can data be utilized in quantitative accident modeling? It is found that the data sources differ in the scope and purpose and they all have their strengths and weaknesses. The existing sources are not perfect and using any of them as the only source of input to a quantitative model seems risky. This was also acknowledged by the participants of the workshops held at IMISS conference, who agreed that marine traffic accident and incident data collection and storing has to be improved in areas such as eliminating underreporting, differences in database taxonomies, and missing and erroneous data. As the improvement of data collection systems is a long term process, an alternative approach might be to improve the models for example by combining multiple sources of data and utilizing additional prior information.