The Coast Guard is the leading agency in the United States for analysing collision statistics and generally preventing marine casualties. In this paper, which was presented at an Institute meeting held in London on 30 November 1966, Captain William C. Foster, Chief of the Merchant Vessel Inspection Division, Office of Merchant Marine Safety of the U.S. Coast Guard in Washington, describes the manner in which accidents of all kinds are investigated. The lecture was illustrated with examples of some of the extremely detailed forms which those involved in marine casualties are required to complete and of the statistical casualty returns; these are not reproduced here.

Marine casualties and accidents, whether or not loss of life is involved, are investigated by the U.S. Coast Guard for the purpose of determining the cause of the casualty and the persons, if any, who are responsible and to obtain information for the prevention of similar casualties. The Coast Guard regulations require the owner, agent, Master, or person in charge of the vessel involved in a marine casualty to notify the nearest marine inspection officer whenever a casualty results which causes physical damage to property in excess of $1500, material damage affecting the seaworthiness or efficiency of the vessel, any stranding or grounding, any loss of life, or injury incapacitating a person for a period in excess of 72 hours. When a casualty occurs in international or foreign waters, this notice is frequently given upon the American vessel's arrival in the continental limits of the United States on forms CG-2692 (Report of Vessel Casualty or Accident) and CG-924E (Report of Personal Injury or Loss of Life).