MR. MASON (IMO 8973461)

MR. MASON is an Offshore Supply Ship built in 1997 and flying the United States of America flag, placing it in its 29th year of service. The vessel reports a gross tonnage of 309 and a deadweight tonnage of 0. This vessel is configured for offshore support operations within its specific service class. The vessel is classed by Other and is not an IACS member. It has been observed in the Middle America and Gulf of Mexico regions. The vessel has a history of one former name and has operated under one former flag. Over the last 36 months it has had 1 port state control (PSC) inspection and no detentions. The most recent inspection was on 19 July 2026.

Frequently asked questions

What is the vessel type of MR. MASON?

MR. MASON is an Offshore Supply Ship. It was built in 1997 and is currently in its 29th year of service.

What are the tonnage specifications for MR. MASON?

The vessel has a gross tonnage of 309. Its reported deadweight tonnage is 0.

Where has MR. MASON been operating recently?

The vessel has been observed in the Middle America and Gulf of Mexico regions. These areas represent its most recent recorded geographic activity.

What is the PSC inspection history for MR. MASON?

Over the last 36 months it has had 1 port state control (PSC) inspection and no detentions, with no deficiencies recorded. The most recent inspection was on 19 July 2026. All-time records show 1 inspection since 2026 and no detentions.

How many times has the ownership of MR. MASON changed?

The vessel has undergone 6 ownership changes during its service life. It has also operated under one former name and one former flag.

Live AIS via Rynda — combined with classification, PSC, sanctions and ownership data.