Thames A Class Rater (scow)

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The Thames A Class Rater is both a historic and modern specialist sailing craft designed for the particular conditions at Thames Sailing Club, on the River Thames at Surbiton in England. The rules[1] refer to the craft as a yacht.

The rig is lofty, supported by standing rigging and usually by runners[2], and the hull is a scow with metal centreplate.

All boats built before 1922 are made from wood whilst those built since are of a different construction.

The rater is extremely fast, planes easily, and is a technically highly challenging boat to sail in anything above moderate wind conditions. It is usually sailed with a crew of three.

Raters have traditionally commuted by river under tow between Thames Sailing Club at Surbiton and Upper Thames Sailing Club at Bourne End, Buckinghamshire.

Rater Development

Over the years raters have developed extraordinarily tall masts and high aspect mainsails to meet the local conditions, and catch the wind above the trees and other obstructions along the banks. Their sails were always large, but originally they had long booms and shorter masts, but over time the booms got shorter and the masts taller. At first they used the so-called balance lug rug, then the Gunter rig, before moving on to the current Bermuda rig. Over the years bamboo spars were replaced first by wood, then aluminium, and now mostly carbon fibre.[citation needed]

Where raters sail

Thames Sailing Club

Upper Thames Sailing Club


Mixed in with large fleets of other boats, the raters are usually seen at the following regattas with very tight, close quarters racing.

  • The Bourne End Week regatta at Upper Thames Sailing Club (seen as the Raters 'national' championships)


Boats past and present

Name Sail Number Dates Description Currently Racing
Original Build Last Rebuild
Kingfisher 1 1909
Alfred Burgoine[3]
2001   Yes
My Lady Dainty 2 1911
Alfred Burgoine
1970 ~ When refurbished in the 1970s by Roger Harrall, boatswain at Raven's Ait, she was clad with a plastic sheath with embossed diamond pattern, similar to non slip floor surfacing, both on her hull and on her decks. She is currently in need of restoration. No
Surf 3 1908
Linton Hope[4]
  Originally named Sea Miaou  


Estelle 4 1902
Alfred Burgoine
  One of the first to have the 45' mast, in 1938  


Carina 5 1902
Alfred Burgoine
2003   Yes
Vanessa 6 1902
Alfred Burgoine
  Originally called Latona Vanessa, she was built to conform to both the "A" and the smaller, slower, "B" rating rules. This results in her being relatively uncompetitive. Yes
Saucy Sally 7 1906
d: Linton Hope
b: Alfred Burgoine
  In 1919, when the rest of the fleet was gunter rigged, she was the first to move to bermuda rig. She was built to conform to both the "A" and the smaller, slower, "B" rating rules. This results in her being relatively uncompetitive. No
Ulva 8 1898
Alfred Burgoine
  She is the oldest rater in existence. Ulva's hull has been used to create the moulds for the current GRP raters  


Caprice IV 9 1910
Alfred Burgoine
  The most successful rater Yes
Viva 10 1910
d: FH Jackson
b: Townsend
  Similar in design to My Lady Dainty. Now lost. No
Dainty Too 11 1922
d: JM Soper
b: Turk[5]
  The last wooden rater built. Bluff bows. Yes
Scamp II 12 1906
d: Linton Hope
b: Hart, Harden and Co
1999 Similar in design to Vagabond, less beamy, and with a longer waterline length Yes
Vagabond 13 1907
d: Linton Hope
b: Townsend[6]
1980s Distinctly narrow beam, came to prominence in Beecher Moore's[7] ownership.

Under Beecher Moore's ownership, Vagabond originated the dinghy trapeze system[8].

Beecher Moore also experimented with a sliding seat, similar to that of the International Canoe. With many "firsts" to her name, Vagabond was the first rater to be commercially sponsored, with the sponsor's logo appearing on her sails.

Spindrift 14   1998 The first of the "Plastic" raters Yes
Atlantis 15   1999   Yes
Osprey 16       Yes
Lady Iona 17       Yes
Sacre Bleu 18       Yes
Wings 19       Yes
Lady Jane 20       Yes
Champagne 21       Yes
Bonito 22       No
Tara 23     Renamed from Caprice V, and built with carbon fibre where technically possible. Yes

The source data for this section is, in part Rater Descriptions from The Rater Association

In the table, "d:" refers to the designer, "b:" to the builder. Where simply a name is present that is the builder


Unusually, for a class designed about a rule allowing wide variation in most design parameters, individual boats are handicapped.

Handicaps will be determined by a handicap committee consisting of the Rater Captain, plus the fastest and slowest helms in the FRP[9] and wooden fleets respectively, based on the results of the most recent Thames Championship. In the event that the Rater Captain is one of the latter four, the closest helm to the Rater Captain in their category shall also be co-opted to the committee.
This committee will meet two or three times a year to decide the handicap of all boats.
The overriding principle that the committee will work to is to encourage the older and slower boats to compete.

The Queens Cup

Presented by Queen Victoria in 1893 the race is set to be nine miles with a four hour time limit. The race takes place on the final day of Bourne End week and is considered the most prestigious race that the raters compete in.

The Association

Thames "A" Rater Association
Thames Sailing Club
Portsmouth Road
United Kingdom


  1. Rules of the The Thames "A" Rater Association
  2. A runner is one of a pair of running backstays. It is rigged between a point towards the boat's quarter and one usually fairly high on the mast. That on the windward side is tensioned to support the mast against the drive of the wind on the sail, while the leeward one is slackened to permit the mainsail to take an efficient shape. So that the tensioning and relaxation can be done rapidly as the boat goes about, a highfield lever is normally used.
  3. Alfred Burgoine was a boatbuilder in Hampton Wick, prominent in Thames yachting, and one of the early developers of the International 14. The yard was immediately below Kingston railway bridge on the Middlesex side.
  4. Linton Hope was an Olympic Yachting Gold Medallist
  5. Turk's Boathouse was in Thames Side, Kingston-upon-Thames; halfway between the road and railway bridges on the north corner of Water Street, just across from the Outrigger public house. In the 1950s, to the north of Turk's boathouse was the firm of Boats and Engines and north of that was T.S.Steadfast. The present building in this position stands on piles in the river where it is on the site of Turk's moorings.
  6. Townsends of Bourne End
  7. Beecher Moore (16 September 1908-10 November 1996) is credited to have designed the first Merlin Rocket in partnership with Jack Holt
  8. Vagabond's trapeze was known as a "Bell Rope"
  9. "FRP" is used instead of "GRP" because at least one boat, Tara, is carbon fibre reinforced. Hence "Fibre Reinforced Plastic"