Technical Information

The Firefly was designed as a low cost one design racing boat over 60 years ago. To ensure that it is still true to its designer the National Firefly Association is always working to ensure that it is still a one design class. Here are some notes that will help you with any technical questions you might have.

Technical Secretary

This role is to ensure that all boats are legal and conform to the rules. As well as helping out owners with modifications and rule related questions. The current Technical Secretary is Mark Tait, so please contact him through the ‘committee’ page if you have any questions.  The other place to get advice (especially detailed “wood” questions) is on the chat page, as a lot more people will view the questions and pass on advice.  So post a message and see what answers you get.  If you have a question you can bet at least 50% of the fleet have had the same question at some point!


The rules cover every aspect of the Firefly no matter how old or new. Every boat must conform to the rules to take part in Firefly Events. The latest rules are downloadable from the here (from the RYA website).

Measurement Certificate

To prove that your boat conforms to the rules you must have a measurement certificate in your name.  If you have purchased a new boat and it has a certificate, it will need to be re-registered to your name.  Contact the RYA and they will issue you a new certificate for a small fee.  

If you buy a new boat from Rondar they will issue you with a completed Measurement Form and builder’s receipt. This you send to the RYA and they will issue you with a Measurement Certificate.  If Rondar haven’t given you a Measurement Form, chase them.  

If you have bought a wooden boat without a certificate, the RYA may have a “historic” certificate.  Contact the RYA technical department and they will advise you.  If the boat has never had a measurement certificate then it will require a full measurement by a RYA measurer.  The RYA will then issue a valid measurement certificate.  

If you have any modifications done to your boat (re-deck, new centreboard case, new rudder, compete rebuild etc) it must be measured by an RYA approved measurer. They will measure your boat and fill out a new Measurement Form and you send it of to the RYA with your original Measurement Certificate. Then the RYA will issue you with a valid and up to date certificate.  

The RYA Technical Deparment’s phone number is 0845 345 0383, 023 8060 4202, 023 8060 4289.  The RYA charge a small admin fee.



These are people selected by the National Firefly Association and the RYA as persons who can measure your Firefly. If you need to have your boat or any part measured contact one of the committee, who will put you in touch with your nearest measurer and arrange to meet you to have your boat measured. It is the boat owner’s responsibility to get the boat to the measurer or cover the measurer’s expenses as they are volunteers.

The current measurers are:



Damian Boreham


Gordon Currey


Brian Herring


Don O’Donnel


Harry Walsh


Steve Greaves


Jamie Marston



 It is a responsible job that requires skill and accuracy to understand the rules. If you are interested in becoming a measurer please contact Mark Tait to have a chat about the role.


There are two sources of Firefly one is Rondar Raceboats who are the only approved class builder. Their website is contact them for details on a new boat. The other source is second hand boats. The best place to find one is on the Firefly Chat Pages in the For Sale and Wanted Section. Otherwise have a look at Yachts and Yachting, Dinghy Trader or Ebay has been known to have a Firefly or two for sale!


To keep the one design, Fireflies have only one sail maker this keeps the costs down and everyone on the same performance. So if you buy a new suit of sails you know that your sails are identical to the fastest boat in the fleet.
The maker is Hyde’s the best place to buy them is through the National Firefly Association as this will save you money and also generate money for the National Firefly Association. Delivery is the same if ordered direct from Hydes. If you are a member of the NFA you get a further £15 discount! To buy sails through the NFA at a discount, contact Will Mason


These are all made by Selden (used to be known as Procter) and use the same design. The Firefly mast and Boom are what is known as “C” section. If you ask any chandler who sells Selden they will be able to supply you with a Firefly mast or boom of the current design. For Selden stockists look at

If you have an older mast most likely it is no longer in production. So to buy a new replacement is not possible the best way to get your hands on one is via the chat page as people often have them lying around in gardens or sailing clubs and are keen to get rid of them. You can always upgrade to the current version very easily with minimal alterations.


If you need a new rudder most rudder manufactures can make a new rudder for you. The NFA have an arrangement with Alan Powell (ex Quicksilver Foils) who will build you one to your spec i.e. lifting/foxed/laminated etc. You get a £20 discount if you are an NFA member. Contact Alan on 01844 201243 or email

If you need a new centreplate either try to locate a second hand one via the discussion forum or for a new one via Rondar.

I hope this has covered most technical aspects of the Firefly if in doubt please do not hesitate to ask Nigel or any member of the Committee and I am sure they will be able to help.

2008 Tuning Guide

Position 2008 Nationals






Paul and Laura Kameen

Tom Malhindine and Alice Currey

Mark Tait and Sally Wakefield

Stuart and Jane Hudson


Biscuit Buffalo 2108 (wood, mark 4)

Bloodhound 2594 (wood, mark 1a)

Dido 498 (wood, mark 4)

Fursty Ferret 3850 (plastic)


Fixed (long)

Fixed (?)

Fixed (long)

Fixed (long)

Bolt to Mast Foot (1)

418 mm

420 mm



Jib Sheeting Pos. (2)

158 cm

162 cm

151 cm

158 cm

Jib Sheeting Pos. (3)

90 cm

91 cm

76 cm

92 cm

Mast Rake (4)

112 cm

113 cm

107 cm

102 cm

Mast Rake (5)

116 cm

116 cm

114 cm

106 cm

Shroud Floppiness (6)


5 inches

4 inches

2 inches

Shroud Floppiness (7)

4 inches

10 inches

9 inches

7 inches

CB bolt to transom (8)

214 cm

215.5 cm

214 cm

212.5 cm

Spreader Length



320 mm

325 mm

Spreader Deflection



620 end to end

125 aft


Measurements are quite accurate, but should be treated as approximate.  Whilst racing upwind, the mast rests against the aft face of the gate in light winds, and the front face of the gate in strong winds.  The change is caused by the kicker and leech tension bending the mast.

1 Centre of centreboard bolt to aft face of the mast (or extension).

2 Distance from aft edge of transom to bearing surface of jib sheeting block or fairlead

3 Lateral distance between bearing surface of jib sheeting.  This distance is limited in 498, as the boat is narrower than the others and the deck layout is mark 4.

4 Set the end of the main halyard level with the vertical centre of gooseneck.  Swing the main halyard to back of boat and measure from end of the halyard, around the traveller to the underside of the transom.  Ignore the width of the bilge keel.  Perform measurement with jib down and forestay slack.  The mast leant against the back of the mast gate.

5 As above, but the mast held against the front of the mast gate.

6 Lean the mast against the front of the gate, with jib down and forestay slack.  Measure the limit of shroud movement at eye level.  (six foot person, boat on trolley).

7 As above, but the mast leant against the back of the gate.  This measurement is influenced by lateral width of the mast gate.

8 This is the distance from the aft edge of transom to centre of centreboard bolt centre.