The Tonnage Measurement Survey

The purpose of this guide is to provide further information concerning the tonnage measurement survey which is a fundamental part of the yacht registration process.

Oceanskies is able to provide the yacht tonnage measurement survey service as part of our complete yacht ownership and registration packages, including both offshore and onshore ownership structures, or we are happy to carry out the tonnage survey as purely a stand- alone service.

We find that the tonnage survey often provoke a number of questions from our clients, not least in respect of why it is needed and why it is required for a production vessel but it also can be confused with other surveys, particularly condition surveys.

British Merchant Shipping Laws require all yachts registered under Part I of the British Register of Ships to have been surveyed by a recognised surveying authority or classification society prior to being registered.

A tonnage survey is also required by all other principal yacht registries with whom we work.

The purpose of the tonnage measurement survey is to ascertain the vessel’s tonnage and principal statistics, in addition to providing independent verification to the registry concerned that the vessel actually exists.

The tonnage survey report provides the registry with the tonnage, dimensions and engine specifications that will appear in the register and on the yacht’s Certificate of Registry.

The tonnage and dimensions of the yacht will determine the application of legislation such as safety and manning requirements, in addition to providing the basis for the calculation of fees or taxes affecting the vessel, such as mooring fees and harbour dues.

A tonnage survey is necessary even for a yacht which may be one of a class or from a production line, (where measurements may have already been taken for a nearly identical vessel).

This is because principal statistics can differ between production yachts and certain unique information will apply to a vessel, such as the Hull Identification Number (HIN), in addition to the engine identification numbers and specifications.

Above all, it should be remembered that the survey is required on a production yacht to evidence the vessel’s existence.

The tonnage of a yacht should not be confused with the actual physical weight of the vessel.

The tonnage is a measurement of the internal capacity of a yacht, in other words it is a volumetric measurement as opposed to a calculation of weight.

The weight of a yacht is known as its displacement, or deadweight (DWT), expressed in Metric Tonnes of 1000 kilograms or Long Tons of 2240 pounds.

The origins of the term tonnage can be traced back to the thirteenth century when data for the carrying capacity of vessels first began to be recorded for vessels carrying cargoes of wine.

The term tonnage derives from the Latin word Tunna which means barrel. Tunnage expressed the number of wine casks that could be carried by a vessel (a tun being the equivalent of approximately 250 gallons of wine occupying around 42 cubic feet).

Virtually all seagoing merchant vessels are measured for individual gross and net register tonnage (known as GRT and NRT respectively).

There are differing ways in which tonnage can be calculated for British registration purposes depending on the legislation governing the individual register.

The majority of the individual British registries require a simplified form of measurement if the yacht is under 24 metres (approximately 79 feet) in length, whilst a more complicated survey must be performed if the vessel exceeds this measurement.

Members of the Oceanskies team are fully authorised by either the Yacht Brokers Designers & Surveyors Association (YBDSA) and/or the Royal Yachting Association (RYA) and/or the International Institute of Marine Surveying (IIMS) to carry out tonnage measurement surveys ‘in house’ to provide Certificates of Survey for the registration of yachts of up to 24 metres in Load Line Length under the red ensign at all British flag ports of registry including:

• Bermuda
• British Virgin Islands (BVI)
• Cayman Islands
• Guernsey
• Gibraltar
• Isle of Man
• Jersey
• The United Kingdom (UK) ports of registry such as London, Southampton, Plymouth etc.

We can also through our partner Transport Malta approves surveyors undertake tonnage surveys for the registration of of yachts of 24 metres or under in terms of Load Line Length in Malta (Valletta).

Our fees for the performance of tonnage surveys for vessels under 24 metres in Load Line Length for British or Malta yacht registration follow:

Oceanskies in conjunction with classification societies such as RINA, Bureau Veritas, ABS and Lloyd’s Register are also able to organise tonnage surveys for the registration of yachts over 24 metres in Load Line Length for the issue of Certificates of Survey and International Tonnage Convention (ITC69) certificates for both British and Malta registration.