This year is the 100th birthday of the X one-design, an evergreen 21ft wooden day boat. It has maintained such steadily popularity that it is on course to break the record for the largest class ever to race in Cowes Week.

The X was designed and built for the Motor Yacht Club (later the Royal Motor Yacht Club) in Poole by Alfred Westmacott. The prototype, named Mistletoe, was built at Westmacott’s yard, Woodnutt & Co at St Helens on the Isle of Wight.

The club ordered four more in 1910, including Madcap (X5, and today the oldest remaining X) and the first ever race was held off Hythe on 3 June 1911.

During the 1920s the class expanded. New boats were built at Woodnutts, at Berthon in Lymington, Kemp in Hythe and Newmans in Poole. As the class grew, there were discussions and controversy about whether to modernise the class and after much debate the gaff rig was replaced with a Bermudan rig in 1928.

After the war boats continued to be built at a steady rate of one or two a year. There are divisions at Poole, Lymington, Yarmouth, Cowes, Hamble and Itchenor.

By 1961 more than 50 Xs competed at Cowes Week. This was the start of the X’s reign as the largest one-design class and only a brief interregnum by the SB3s between 2005 and 2007 has ever eclipsed it.

No new boats have been built in recent years – the only new boat was not admitted to the class, a longer story to be outlined in our July issue. The boats must be traditionally built and the cost would be around £40-50,000. A good secondhand boat can be bought for £10-20,000, in some cases less.

The newest in existence is this beauty, which I visited at Parkstone a few weeks ago as she was about to be launched for the season by owner John Wilson. She is called Saranna, and is a fascinating story.

Back in 2000, John’s job as a chartered surveyor took him to Lyme Regis, where he looked in on the boatbuilding school. He was so taken with what he saw that he applied for early retirement and enrolled.

His first idea was to build a Flying Fifteen, but everyone he talked to said it would be competitive and a friend suggested an X boat. When he sent off for the plans, John had never seen or sailed and X and no idea that the rules were explicit about which yards were permitted to build new boats.

After discussion with the chairman of the technical committee, he was given the go-ahead, but says: “I was ruled with a rod of iron. There were four inspections and everything was checked: the plank dimensions, the thickness of the planking, the density of the wood.”

From the start, John did everything himself, sometimes with the help of another student. He did the lofting, made the frames and stuck mainly to traditional build methods. Saranna’s planks are coppernailed and caulked with cotton and epoxy was used only laminate the stem.

The whole build took John six years and Saranna was finally launched in 2007. Since then he has been concentrating on getting the boat up to speed, a difficult feat in a class that has some very experienced, technically astute -and often rather elderly – winners.

More on the fascinating century of the XOD, and its sometimes contentious history in our next issue.