Registration & Sail Numbers

Registration & Transfers

To register your boat and get a sail number or to transfer ownership of a boat please read the following Registration Procedure Information Sheet. Once you have read this please print off the Registration/Transfer Form and send it to the registrar WITH the measurement book for your boat.  NOTE: There is NO CHARGE for transferring ownership between siblings.


Sail Numbers:  If you need to buy new sail numbers these can be purchased from any sail maker directly such as:

  • Quantum Sails
  • NB Sail sports
  • OptiParts
  • North Sails

Missing your measurement book?

If you are missing the measurement book for your boat please check this list. Please contact the AIODA registrar as detailed below. Measurement Books in Registrar's Files


Lost your measurement book?

If you have lost your boat's measurement book you can order a replacement from IODA.  Please email the International Secretary, Fiona Kidd - info [at] she will need to know the ISAF plaque number of your boat.


Contact AIODA Registrar 

Emma Short

PO Box 1109

Stirling SA 5152

Ph: 0422995711

Contact by registrar [at] (Email)


Location of ISAF Plaque


Sample ISAF Plaque

Please see below an example of your ISAF Plaque.


Class rules for Registration & Measurement

The relevant section of the class rules:-

2.4 Registration and Measurement Certificate

2.4.1 No boat is permitted to race in the class unless it has a valid measurement certificate.

This rule may be suspended in the case of charter boats at any event with the permission

of the IODA Executive Committee.

2.4.2 Each National Authority shall issue sail numbers which shall be consecutive and the

number shall be preceded by the national letters. Numbering may restart at 1 on reaching

number 9999. A National Authority shall issue a sail number only on receipt of evidence

that the building fee has been paid.

2.4.3 The certificate is obtained as follows:

(a) The builder shall have the hull measured by a measurer officially recognised by his

National Authority. The Registration Book with the ISAF International class fee

receipt, builder's declaration and hull measurement form section completed shall be

supplied to the owner of the boat.

(b) The owner shall apply to the appropriate National Authority for a sail number enclosing

their Registration Book with builder's declaration and building fee receipt. The

National Authority shall enter the sail number in the Registration Book.

(c) The owner is responsible for sending the Registration Book with the builder's declaration

and all measurement form sections completed to his National Authority, together

with any registration fee that may be required. On receipt of this the National

Authority shall complete the measurement certificate section of the Registration Book

and return it to the owner. Note that where a National Authority prefers to issue its

own certificate this shall be firmly fixed to, and mentioned in the Registration Book.

2.4.4 Change of ownership invalidates the measurement certificate but shall not necessitate

remeasurement. The new owner shall apply to his National Authority for endorsement of the

certificate/Registration Book returning it with any re-registration fee required and stating

the necessary particulars. The measurement certificate/Registration Book shall then be returned to the owner.



Sail Number Style/Colour - Racing Rules of Sailing Appendix G

G1.2 Specifications

(a) National letters and sail numbers shall be in capital letters and Arabic numerals, clearly legible and of the same colour. Commercially available typefaces giving the same or better legibility than Helvetica are acceptable.


YA Equipment Regulation 4 - Boat Identification

In accordance with Yachting Australia Equipment Regulation 4 all boats are required to have clearly marked externally on their transom or on both outboard sides of the hull the following information:

a)      The name of the boat in letters/figures at least 50mm high and 8mm thickness;

b)      The registered sail number;

c)      Name of the owner’s YA affiliated Club. Note: while the name of the Club may be abbreviated it is recommended the name be in full where possible as another club may also use the same abbreviation.