A Unique Vessel Identifier (UVI) is a unique reference number for registered ships that allows for quick and accurate vessel identification. A UVI can help to trace and verify a fishing or associated vessel’s activity over time — regardless of changes in name, ownership, or flag.

International Maritime Organization (IMO) numbers are an internationally recognized type of UVI. But for vessels not eligible for IMO numbers, other types of UVIs exist — such as the TUVI (Tuna Unique Vessel Identifier) or the ISSF-UVI (UVI issued by ISSF).

This vessel list includes all tuna fishing vessels with an IMO number as well as vessels not eligible for an IMO that are using either a TUVI or an ISSF-UVI as an alternative UVI.

An asterisk (*) after the vessel name indicates that the vessel has met all of these conditions:

UVI/IMO Vessel List

View all of the vessels in the UVI/IMO and sort the list.


About IMO Numbers

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. IMO numbers are issued free of charge.

For ships, the IMO number remains linked to the hull for its lifetime, regardless of changes in name, flag, or owner.

This vessel list shows known IMO numbers for tuna fishing vessels that operate in various oceans. The information in this list has been compiled from a variety of sources, including the IHS Register; the vessel registers maintained by IATTC, ICCATIOTCWCPFC and FFA; and 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. We encourage you to email [email protected] to notify us of any errors or omissions. We will diligently review and respond to notifications.


About Other UVIs

Unique vessel identifiers (UVIs) such as IMO numbers help to improve maritime safety and security and to reduce illegal activities.

Some vessels, however, cannot obtain an IMO number because they are not large enough or are not authorized to operate outside waters under national jurisdiction.

This vessel list has been developed to include tuna fishing vessels that are not eligible to obtain an IMO number.


Get IMO Number

IMO Numbers & Transparency in the Fishing Industry Document

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.

View our infographic showing 2011–2020 growth in the percentage of large-scale, tropical-tuna purse-seine vessels that have IMO numbers.

How to Get an IMO


Get ISSF-UVI Number

To apply for an ISSF-UVI number, download the ISSF-UVI application form below, and submit the completed form to [email protected] along with a copy of all vessels’ fishing licenses.

Note: ISSF-UVI numbers will only be issued to vessels that cannot obtain an IMO number and do not have a TUVI number.

ISSF-UVI Application Form