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Measurement Certificates

Class Measurement Certificates & Change of Ownership

The Racing Rules of Sailing require that every boat must have a valid measurement certificate. Australian Sailing issues measurement certificates for the following classes:

Dinghy Keelboat
420 5.5 Metre
470 Dragon
Contender Etchells
OK Dinghy  

Measurement certificates for other classes are issued by the class association.

New boats

New boats also need a measurement certificate. For most classes, the owner must apply for a measurement certificate using the button below. Australian Sailing will then issue a sail number, update the class register, issue the measurement certificate to the owner, and send a copy to the class association.

OK Dinghies and Dragons: before a measurer can complete the measurement form for a new OK Dinghy or Dragon, the owner needs to apply to Australian Sailing for a sail number. Click here to apply for a sail number.

Second hand boats (change of ownership)

When you buy a second-hand boat, the measurement certificate is invalidated and you must apply for a new measurement certificate. Once you do so, Australian Sailing will update the class register, issue a new measurement certificate, and send a copy to the class association.

You don’t need to do anything else to record the change of ownership.

Sail numbers

New boats are always allocated the next available sail number. Class rules require Australian Sailing to issue numbers sequentially, so we are unable to accommodate requests for special numbers, or issue numbers out of sequence.

A second hand boat will already have a sail number allocated, which stays with the boat for its lifetime.

What you need to apply

To apply for a measurement certificate, you’ll need:

  • An electronic (scanned) copy of the boat’s measurement form
  • The boat’s World Sailing (ISAF) plaque number
  • The boat’s sail number, if it has one

If you don’t have the measurement form, please email as we may have a copy on record. Otherwise, you’ll need to contact your class association and arrange for your boat to be re-measured.

Please note: turnaround time for measurement certificates is five business days. Please ensure you apply for your certificate early to avoid problems.

Apply now

Frequently asked questions

Measurement certificate applications will be processed within five working days of receipt. To speed up the process, make sure you submit all required documents and information with your application.

As our offices are closed over the summer holiday period (from 21 December to 8 January), you will need to submit your application no later than Friday, 15 December to guarantee your certificate is issued before we close.

You need to apply for a new measurement certificate; see above under “Change of Ownership”.

First, send an email to as it’s possible that we have a copy on record. If not, you’ll need to contact your class association and have the boat re-measured.

Optimists only: the Optimist class rules allow replacement measurement forms to be issued. More information is available on the Optimist website:

If your boat hasn’t been registered in Australia before, you’ll need to apply for a certificate as though it is a new boat. You’ll get an Australian sail number and certificate.