Failure of Doubler-Plated Hull Likely Cause of Sinking of Fishing Vessel


Grace Marie underway before the sinking (Source: Paul Spillane)

​​Grace Marie underway before the sinking (Source: Paul Spillane)​

​​WASHINGTON (July 11, 2023) — The failure of the doubler-plated hull under the engine room likely caused the flooding and sinking of a fishing vessel near Gloucester, Massachusetts last year, the National Transportation Safety Board said Tuesday.

The fishing vessel Grace Marie was transiting to fishing grounds on July 8, 2022​, when the engine room began flooding. The seven-person crew was unable to remove the water with the vessel’s bilge pumping system. The crew abandoned the vessel in a life raft and was rescued by a Good Samaritan vessel. The vessel eventually sank and was a total loss valued at $650,000. No injuries were reported. 

​The external area of the hull along the keel and under the engine room was covered with steel doubler plating to cover and reinforce areas of deteriorated steel. It was installed 8-10 years before the vessel sank. 

​It is common for uninspected commercial fishing vessels such as the Grace Marie to use doubler plating to repair and reinforce damaged or wasted underwater hull sections. Doubler plate repairs can lead to increased stress concentrated in the area of the repair. Doubler plating also inhibits the ability to assess the true condition of the hull.

The NTSB determined the probable cause of the flooding and sinking of the Grace Marie was uncontrolled flooding of the engine room from an undetermined source, likely a failure of the doubler-plated hull below the engine room.

“Although doubler plating can be used as a temporary repair solution, it is not generally suitable as a permanent repair for a vessel’s hull,” the report said. “Vessel owners should crop out wasted steel on the hull and replace it by inserting new plating instead of covering it up with doubler plating.”

Marine Investigation Report 23-13 is available online.


To report an incident/accident or if you are a public safety agency, please call 1-844-373-9922 or 202-314-6290 to speak to a Watch Officer at the NTSB Response Operations Center (ROC) in Washington, DC (24/7).