The Office of Marine Safety (OMS) investigates and determines the probable cause of major marine casualties in US territorial waters, major marine casualties involving US-flagged vessels worldwide, and marine accidents involving a public (government) vessel and any other vessel. Additionally, the NTSB fulfills US obligations with regard to foreign accident investigations, established under the auspices of the International Maritime Organization (IMO), by participating with the Coast Guard as a substantially interested State in investigations of certain serious marine casualties involving foreign-flagged vessels in international waters. The office also may investigate accidents when the Board determines that they are catastrophic or the accident involves problems of a recurring character.
Investigations of ‘Major Marine’ Casualties
The US Coast Guard conducts preliminary investigations of all marine casualties and notifies the MS when an event qualifies as a major marine casualty, which is a casualty that results in:
- the loss of six or more lives.
- the loss of a mechanically propelled vessel of 100 or more gross tons.
- property damage initially estimated to be $500,000 or more.
- a serious threat, as determined by the Commandant of the Coast Guard with the concurrence of the NTSB Chair, to life, property, or the environment by hazardous materials.
Independent Marine Investigations
The NTSB is the only federal organization that performs independent, comprehensive, and transparent multidisciplinary investigations to determine the probable cause of marine accidents, with the goal of making safety recommendations to prevent similar events from occurring in the future. The thoroughness and independence of these investigations maintain public confidence in marine transportation systems and provide policymakers with unbiased analysis.
After investigating each major marine casualty, the MS identifies safety issues and releases an investigation report with a probable cause, which may include safety recommendations to federal government agencies (such as the Coast Guard), state agencies, vessel owners and operators, vessel classification societies, or maritime industry organizations. We may also issue close-out memos, which note the general facts of an accident, in cases where we do not produce an investigation report.
Divisions
MS comprises the Investigations Division and the Product Development Division.
Investigations Division
The Investigations Division coordinates and oversees investigations of major marine casualties. The division manages the multidisciplinary go teams that launch to accident sites, collect information, and analyze collected information to determine the probable cause of an accident. It is comprised of investigators that specialize in disciplines including navigation and ship handling, marine propulsion and ship systems, naval architecture, lifesaving and survival factors, and human factors.
Product Development Division
The Product Development Division works with the Investigations Division to produce all marine investigation reports, safety alerts, and safety recommendations reports. The division, which consists of technical writer editors, is responsible for quality control of all products and ensuring adherence to agency publications guidelines. The division is also responsible for drafting and editing the annual Safer Seas Digest publication, as well as responding to notices of proposed rulemaking, requests for reconsideration, and general correspondence.
Updated April 7, 2025
