Tonnage

Tonnage Certification & Vessel Registration

MECAL is approved by the Maritime and Coastguard Agency (MCA) and other recognised authorities to undertake Tonnage Measurement Surveys and issue Certificates of Survey for Tonnage and Measurement.

These certificates are required for the registration of vessels and, where applicable, for commercial certification under the Small Commercial Vessel Codes.

What is Vessel Registration?

In the UK, vessels under 24 metres load line length may be registered under one of the following parts of the UK Ship Register:

Part I – UK Ship Register
Suitable for both commercial and private vessels, including those operating internationally.
Part III – Small Ships Register (SSR)
A simplified register intended for UK-based leisure vessels only.
Part III – Small Ships Register (SSR)
The Small Ships Register is designed for private individuals who are ordinarily resident in the UK and who use their vessel solely for pleasure.

Key characteristics and limitations include:

Available only for vessels under 24 metres load line length
Does not record proof of ownership
Not permitted for commercial use
May not be recognised by all foreign authorities, particularly outside nearby European waters
Most suitable for short sea passages, such as cross-Channel or near-coastal operations

Part I Registration

Part I registration is the most comprehensive and internationally recognised form of UK vessel registration and is required for most commercial operations.

Benefits include:
Suitable for international voyages
Required for vessels coded under the Small Commercial Vessel Codes
Provides formal evidence of title and ownership
Enables the vessel to be mortgaged
Recognised by flag administrations and port authorities worldwide

Part I registration is valid for five years, after which re-registration is required. While no further tonnage survey is normally required at renewal, a new Certificate of Survey for Tonnage and Measurement will be needed if the vessel undergoes significant modification, such as:

Further information on Part I registration and the application process can be found on the UK Ship Register section of the government website.

What is Tonnage?

Tonnage is a measure of a vessel’s internal volume, not its weight. It is used to:
Determine registration and certification requirements
Establish applicable regulatory thresholds
Calculate registration fees
Support classification and statutory compliance

MECAL’s tonnage surveys are conducted in accordance with applicable UK and international standards and are accepted by the MCA and other authorised administrations.

When Do I Need a Tonnage Survey?

A Tonnage Survey and Certificate of Survey for Tonnage and Measurement are required in a number of common circumstances, including:
Registering a vessel for the first time on the UK Ship Register (Part I or Part III where applicable)
Registering a vessel for commercial use, including coding under the Small Commercial Vessel Codes
Changing a vessel’s registration, such as moving from private to commercial use
Re-registering under Part I where no valid tonnage certificate is held
Following significant modifications to the vessel, including:
Engine or propulsion changes
Structural alterations
Enclosure or removal of enclosed spaces
Flag State or administrative request, where updated tonnage information is required

A new tonnage survey is not normally required at Part I renewal unless the vessel has been materially altered since the previous certificate was issued.

If you are unsure whether your vessel requires a new tonnage survey, MECAL can review your vessel’s details and advise on the most appropriate route before any application is submitted.

Note A new tonnage survey is not normally required at Part I renewal unless the vessel has been materially altered since the previous certificate was issued. If you are unsure whether your vessel requires a new tonnage survey, MECAL can review your vessel’s details and advise on the most appropriate route before any application is submitted.