In an effort to better identify accident causes and to serve as an input to the development of an effective collision research program, the Coast Guard initiated a program to investigate twelve pleasure boat collision type accidents during calendar year 1976. Current research efforts are directed towards investigating visibility, control station design and noise as factors which may be related to collision accidents; therefore, the selection of accidents investigated were based on initial indications that one of the above mentioned parameters could have been influential in causing the accident. This report contains the following: A synopsis of the accident reporting system; The methodology used to screen and select accidents for investigation; An overview of the type of data acquired during the investigation; A summary of important parameters of each boat involved; Narrative summaries of each selected accident; and Complete reports of each accident investigated.