18ft Skiff

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Current Specifications
File:Churchills flying 2005-09-17 1280x983.jpg
International 18' Skiff Churchills on Sydney Harbour
Crew 3 (triple trapeze)
LOA 8.9 m (29 ft)
LWL 5.49 m (18.0 ft)
Beam 2.0 m (6 ft 7 in)
Hull weight 155 kg (340 lb)
Main & Jib area Unlimited, typically
26–32 m2 (280–340 sq ft)
Mainsail area 9.28 m2 (99.9 sq ft)
Spinnaker area Unlimited, typically
61–73 m2 (660–790 sq ft)

The 18ft Skiff is considered the fastest class of sailing skiffs. The class has a long history beginning with races on Sydney Harbour, Australia in 1892. The boat has changed significantly since the early days, bringing in new technology as it became available. Because of the need of strength, agility and skill, the class is considered to be the top level of small boat sailing. Often this boat is called the "Aussie 18" due to its inherent connections to Australia. It is the fastest conventional non-foiling monohull on the yardstick rating, with a score of 675, coming only third after the Tornado and Inter 20 (Both multihulls).


The 18ft Skiff has come a long way in more than 100 years of continuous development.[1] From heavy boats carrying a crew of ten or more, to today's high-tech, light-weight, high performance design. Parts of the history of the early days of skiff sailing, between 1892 and 1945, is found on the pages of the Australian 18 Footers League.

The modern 18 ft Skiff

Today there are two modern hull designs racing. The "International 18" is based on a design by Iain Murray, while the B18 was designed by Julian Bethwaite. The Australian 18 Footer League allows only the International 18, with the annual JJ Giltinan International Trophy contended with the one design Murray hull. The European Class Association allows both designs to compete against each other.

Although there are differences in the sailing aspects of the two designs, their measurements are very close, with a waterline length of 18 ft (5.49 m) and an average beam of 6 to 8 feet (1.83 to 2.44 m), not including the wings. With wings the maximum beam is 14 feet for the "International 18" and 18 feet for Open 18's sailed at Sydney Flying Squadron. When the boat is dry it should weigh not less than 375 lb (170 Kg) including wings, foils (centreboard and rudder) and the number one rig of sails, spars and ropes.

In the 1980s and 90's wings were widened to the extreme - some boats having maximum beam of 26 feet. Such wings proved unmanageable, with the crews too much on the brink of disaster for consistent success.

While true 18' skiffs have no sail area or mast height limitations, the limit that the 18 footer League has specified for their one-design sub class is a maximum mast height of 33 ft (10 m), truly powerful on an 18' hull. The entire rig, which supports sails with unlimited area, is controlled by three trapezing crew members.

The boat will plane upwind starting at a true windspeed of about 8 knots, and off the wind can reach speeds of double the true windspeed. This is possible through the very high sail-carrying power to total weight ratio, which is above 30% with the no. 1 rig and approaches 40% with the no. 3 rig (for reference, a 30% ratio is needed to plane upwind and a 10% ratio is needed to plane at all. Most cruising boats have a ratio under 5%).

Open 18' Skiff Synergy!
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Open 18’ Skiff Synergy! fitted with hydrofoils

Future evolutions of skiffs may incorporate hydrofoils, such as Synergy! skippered by Michael Carter above.

In Australia, there is a fleet of approximately 20-25 18 Foot Skiffs at the "League" club in Sydney. Sydney's other traditional 18 Foot Skiff club, the Sydney Flying Squadron, has a small fleet and there are several boats in the state of Queensland.

However, the 18 ft skiff is not without its dangers. The high speed makes it hard to handle and requires extremely fast reflexes and a broad awareness of your surroundings in order to anticipate changes. Major accidents can occur with inexperienced and experienced sailors alike.

The 18 ft skiff is currently one of the fastest monohulls on earth. With its massive sail-plan of over 100 square meters on the no. 1 rig and three crew members on trapeze it can outperform nearly every monohull on the water. It combines extreme speeds with an element of danger and is thought by many to be one of the biggest spectacles in sailing.

Each year the JJ Giltinan International Trophy is contested on Sydney Harbour to decide the de-facto world champion of the class. Typically the event was dominated by Australia and occasionally won by New Zealand, but in recent years entrants such as the USA's Howie Hamlin have taken out the title, displaying the classes growing international appeal.

The Historical 18’ Skiff

In Sydney and Brisbane Australia there has been a revival of the early days of 18’ skiff sailing. Replicas of famous 18’ skiffs from the period of 1930 through to 1950 have been built using original techniques, including wooden hulls and spars, gaff rigs, several-piece spinnaker poles and unrestricted sail area. These boats race under the rules of the Australian Historical Skiff Association, which bans wings, trapezes, cleats for controlling ropes for the mainsail, jib and spinnaker, and most of the other modern equipment which makes sailing easier.

The class has proved very popular with former sailors of modern 18’ skiffs who, to quote a class champion John Winning, are looking for a challenge because “the modern boats have become too easy to sail”.

The historical 18’ skiffs have a crew of between 6 and 9, which often leaves an opportunity for visiting sailors to have a ride.The AHSSA website listed below has more details.

At present the class is raced out of the Sydney Flying Squadron in Sydney and the Brisbane 18 Footers Sailing Club Inc. There are also bi-annual challenges against the New Zealand 18’ Kauri-Clinker M Class.


  1. See section 16.10 of Bethwaite, Frank (2007). High Performance Sailing. Adlard Coles Nautical. ISBN 978 0 7136 6704 2. 

See also

  • The following book provides a comprehensive description of technological developments up to 1993 that have been incorporated in the 18 ft Skiff and other high-performance boats: Bethwaite, Frank (first published in 1993; new edition in 1996, reprinted in 2007). High Performance Sailing. Waterline (1993), Thomas Reed Publications (1996, 1998, and 2001), and Adlard Coles Nautical (2003 and 2007). ISBN 978 0 7136 6704 2.  The book also covers the history of the 18 ft Skiff and of high-performance sailing in general, as well as the sailing techniques required to achieve high performance.

External links

fr:18 pieds