Achilles Yacht Owners Association
This site is for all those who are interested in sailing yachts built by Butler Mouldings.
Saturday, March 14, 2026
Possible moderation delays
Tuesday, March 10, 2026
Insignia and Sail numbers
A post in response to a query on FaceBook and to while away some time as I wait to go sailing.
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| Unlike those produced by many sailmakers the "A" of the insignia should be pointed, not square. |
Why have Sail numbers?
Whilst designers and builders of boats probably like to have numbers on their boats, at least if they are selling well, the main driver for sail numbers is racing and to a lesser extent for search and rescue (SAR) so that boats can be positively identified.
Race committees need to know which boats started and when they finished and if there are a lot of boats they don't have time to read boat names. Also they need to be able to identify rule breakers, particularly on the start line and this led to strict rules as to size of the numbers (iirc originally related to luff length) and positioning of the numbers so they can be seen, "keen" owners still tried their best to hide them by positioning the numbers as far back on the mainsail as allowed so they would not be as visible if they were over the line at the start.
For series built boats from a single builder - like the Achilles Boats and the Mirror dinghy #10784 I bought as a kit in 1967 - the normal thing was for the builder to allocate the hull number as the sail number this worked fine, at least initially.
Problems arise when there is more than one builder and at this point the numbers were and are usually allocate by a formal class association but this does not work for "one off" boats, or perhaps for boats built in multiple countries. It can also be problematic in mixed fleets where the number is qualified by class insignia, if there is one. At this point some order needed to be bought to the situation and numbers started to be allocated by national authorities or their nominees.
The current rules by "World Sailing" can be found under RRS Appendix G here.
Country specific numbers.
Were introduced early on, that for UK was for years "K" placed above the numbers as a prefix. Then for some reason it was replaced by a more expensive (sailmakers charge per letter/number) and cluttering "GBR".
UK Issuing authorities.
Whilst class associations continue to issue numbers for many boats, national authorities and their delegates' took over many. In UK there are three, the Royal Yachting Association (RYA), The Royal Ocean Racing Club (RORC) and the Clyde Yacht Clubs' Association (CYCA)..
RYA
As the national authority the majority of modern sail numbers for cruising offshore yachts are allocated by the RYA, modern ones are suffixed by L, N or X and M for multihulls.
RORC
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| The RAFSC UFO34 "Black Arrow" named for 111 squadron "The Black Arrows" with its RORC members sail number and then UK identifier. ©️unknown. |
0 - 999 Allocated to members of RORC.
1nnn RORC Class 1 boats.2nnn Class 2 boats (including 2 tonners).3nnn Class 3 boats (including one tonners).4nnn Class 4 boats (including 3/4 tonners).5nnn Class 5 boats (including 1/2 tonners).
From 1993 the suffix "R" was added, I don't know if the class number is still used but older boats will still have them as these numbers, unlike the members numbers, stay with the boat.
CYCA
Are approved under RRS Appendix G and have the suffix "C", they can still be obtained.
Achilles Yachts.
There is the possibility of confusion as each model has it's own series so for example Sancerre A9m #21 has the same Insignia and number as the similarly sized A840 "Tocviria".
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| Sancerre A021 also has an RYA allocated number. Here displayed on the guard rails for the 2019 Jester, useful for SAR - hopefully to disregard Sancerre as not the boat in trouble! Pic J. Lashbrook. |
The following Achilles have CYCA numbers allocated although they do not necessarily display them, note that this is not complete, the listing by class is missing some boats that are included in the listing by sail number. If you are trying to track down a boat and it is not here see https://www.cyca-online.org.uk/handicaps.asp.
| One of several A24s with a Clyde sail number and the correct Insignia. probably hull #317 "Kismet" (pic pinched from Facebook) |
| A peculiarity of sails sold with Achilles boats and some replacements is that they had leading zeroes to make 3 digits. Sancerre's old star cut. Pic J. Lashbrook. |
Monday, January 12, 2026
For sale and wanted
Due to lack of use and a lot of old adverts I have removed the "For sale" and "wanted" pages from the site.
Adverts can be posted as comments to this post or by emailing them to me and I will add them to this section.
Wednesday, December 3, 2025
RYA SafeTRX discontinued.
It didn't last long! Best update your data before the App etc. disappears and they transfer the data. Back to CG66?
Friday, August 22, 2025
Hull Identification Numbers (HINs)
For the avoidance of duplication here and hopefully on Flikr and the Facebook group where the question comes up occasionally.
Hull Identification Numbers (HINs) are a structured number identifying the maker of a boat and some other information (see below). It was introduced after the Achilles boats were made and was not mandatory until 1998. Butler would never have had a makers number etc so the boats can not have a formal HIN.At the factory hulls were not generally identified the original sail number being the hull number.
The Google AI description looks to be correct:
A boat's Hull Identification Number (HIN) is a unique 12 or 14-character code that serves as a serial number for the boat, similar to a Vehicle Identification Number (VIN) for a car. It's used to identify the boat and track it for various purposes, including registration, defect notifications, and sales.
Key aspects of a HIN:
Permanent Marking: The HIN is permanently etched or molded into the boat's hull, typically on the starboard side of the transom and also hidden elsewhere on the boat.
Structure: The HIN typically includes a manufacturer's code, a unique serial number, and sometimes details about the year and place of manufacture.
Historical Context: HINs were introduced in the US in 1972 and in the EU in 1998.
Relevance to Recreational Craft Directive (RCD): The RCD requires all boats built after 1998 to have a HIN, which helps in ensuring compliance with safety and environmental standards.
Manufacturer's Identity Code (MIC): For boats built in the UK, the MIC is a unique three-letter code identifying the manufacturer, registered with British Marine.
Uses: HINs are used for registration, tracking recalls, and facilitating boat sales.
My note: usually asked for by insurance companies, the SSR and others but like all vintage boats there is nothing to give.
Monday, July 28, 2025
Ron Dustow
Sadly, I have to tell everyone that Ronnie Dustow passed away on Sunday 20th July 2025, quietly at home. He had been diagnosed with terminal cancer in December having fought off a different cancer a few years ago.
Tuesday, June 24, 2025
A24 gear for sale 24 June 2025
“Achilles 24 parts for sale due to boat break up; Mast and Rigging must go in next 3 weeks, reasonable offers accepted. Also other parts on request. Location; Hamble. e mail; allangbooth@btpenworld.com — phone 07771 987570”


