An MBI is the highest level of investigation in the Coast Guard. Upon completion of the investigation, the Board will issue a report to the Commandant with the evidence collected, the facts established, its conclusions, and recommendations.

During the course of the MBI, the Board will work to determine:

• The cause of the casualty, including the cause of any death.
• Whether an act of misconduct, incompetence, negligence, unskillfulness, or willful violation of law committed by any individual licensed, certificated, or documented has contributed to the cause of the casualty, or to a death involved in the casualty, so that appropriate remedial action may be taken.
• Whether an act of misconduct, incompetence, negligence, unskillfulness, or willful violation of law committed by any person, including an officer, employee, or member of the Coast Guard, contributed to the cause of the casualty, or to a death involved in the casualty.
• Whether there is evidence that an act subjecting the offender to a civil penalty under that laws of the United States has been committed, so that appropriate action may be undertaken to collect a penalty.
• Whether there is evidence that a criminal act under the laws of the United States has been committed, so that the matter may be referred to appropriate authorities for prosecution.
• Whether there is need for new laws or regulations, or amendment or repeal of existing laws or regulations, to prevent the recurrence of the casualty.

The Coast Guard MBI is working in close coordination with other national and international authorities including the United States National Transportation Safety Board, Canadian Transportation Safety Board, French Marine Casualties Investigation Board, and United Kingdom Marine Accident Investigation Branch.  

Original source can be found here