Tonnage 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.

Yachts under 24 metres in length measured under the simplified form of measurement can be surveyed by independent surveyors operating under the auspices of the Royal Yachting Association and the Yacht Brokers, Designers & Surveyors Association (YBDSA) in addition to the approved classification societies, such as Bureau Veritas and Lloyd’s Register.

Oceanskies can perform these surveys in house utilising the services of its own affiliate tonnage surveyor for registrations at all popular ports of registry including but not limited to the following:

  • UK – i.e. London
  • BVI
  • Cayman Islands
  • Isle of Man
  • Jersey
  • Guernsey

Our Malta leasing programme remains popular and in cases where owners choose a British flag instead of a Maltese flag for the yacht we will obviously be able to perform these tonnage surveys.

In cases where our in house affiliate surveyor is unable to survey yachts under 24 metres for tonnage purposes we shall arrange the survey through one of the main survey societies.

Yachts over 24 metres in length are measured under the International Tonnage Convention (ITC 1969). The basic premise of the ITC 69 is to provide a universally accepted method to measure the tonnage of vessels. Tonnage surveys for yachts over 24 metres can only be carried out by one of the approved classification societies.

For yachts over 24 metres in registered length we co-ordiante tonnage survey arrangement with class through the shipyard for new build vessels and with class directly in respect of existing vessels.

In conclusion Oceanskies effectively acts as a facilitator for the performance of yacht tonnage measurement surveys, balancing the need for the survey to be arranged as quickly as possible in order that the yacht registration process is not unduly delayed, whilst ensuring that the client is paying a reasonable price for the survey.

We welcome enquiries from yacht owners or their representatives require tonnage surveys for their vessel regardless of the vessel size or location.

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Guernsey Office

Oceanskies Limited

Castle Emplacement

St. Peter Port, Guernsey GY1 1AU

Channel Islands, Great Britain

Malta Office

Oceanskies (Malta) Limited

56, Ground Floor, Europa Centre

Saint Anne Street,

Floriana FRN 9011, Malta


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