The International Maritime Organization (IMO) number is a unique identifier for vessels. IMO numbers help to improve maritime safety and security and to reduce illegal activities. For ships, the IMO number remains linked to the hull for its lifetime, regardless of a change in name, flag, or owner. This database shows known IMO numbers for tuna fishing vessels that operate in various oceans. The information in this database has been compiled from a variety of sources including the IHS Register, the vessel registers maintained by IATTC, ICCAT, IOTC, WCPFC and FFA, and from industry sources. IMO numbers have been validated against the IHS Register. However, some fields such as Flag or Vessel Type do not seem to be updated in the IHS database as quickly as they are in the RFMO vessel records. In such cases, the RFMO data have been used. ISSF does not warrant that all information is accurate or complete. ISSF invites any user to notify us of any errors or omissions; ISSF will diligently review and respond to such notifications.

A after the vessel name indicates that the vessel has sunk, has been scrapped or otherwise permanently transferred out of the tropical tuna fishery; that the vessel had not ceased fishing operations prior to January 1, 2010; and has provided a Vessel Removal/Replacement Form.

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Any fishing vessel, refrigerated cargo vessel (reefer), or supply vessel 100 gross tons (GT) or over is eligible for an International Maritime Organization (IMO) ship number.

In addition, any fishing vessel, refrigerated cargo vessel (reefer) or supply vessel 12 meters in length or over, authorized to operate outside waters of national jurisdiction (within an RFMO or another country’s 200-mile exclusive economic zone [EEZ]), including those with a non-steel hull construction, is eligible for an IMO number.

IMO numbers are issued free of any charge. 

See our infographic showing the increase in IMO numbers among large-scale, tropical-tuna purse-seine vessels.

Click here for instructions on how to acquire an IMO Ship Number for your vessel.