The first large-scale catamaran was the brainchild of a multi-talented Irishman more than 300 years ago, writes Mary Mulvihill.

Rewind 340 years, to July 1663, and the world's fastest ship is racing into Dublin Bay. Designed and built in Dublin, it is a strange vessel, with not one but two hulls. Yet despite its odd construction, the aptly named Experiment has just beaten the Holyhead mailboat by a full 15 hours.

This high-speed catamaran was the brainchild of the multi-talented Sir William Petty (1623-1687). His double-bottomed boats were ahead of their time, however, and it took another 300 years and the development of modern materials before high-speed catamarans were again seen in Dublin Bay.

Petty, who came to Ireland as physician-general to Cromwell's army, is renowned as the father of political economy and an advocate of the new scientific revolution. He is better remembered in Ireland, however, as Cromwell's secretary and mastermind of the first detailed land survey of this country.

He was born in England to a relatively lowly family and went to sea as a cabin boy, but his subsequent rise to prominence was meteoric if convoluted. By 27 he was both professor of anatomy at Oxford, and professor of music at a London college.

Yet one of his life's ambitions was to design a fast boat and it was during his Irish sojourn that he found time, despite a busy surveying and scientific schedule, to experiment with boat design.

Boat-building then was a traditional craft, the knowledge handed down from father to son. Instead, Petty, who introduced the modern scientific revolution to Ireland with its emphasis on experiments, decided to test small-scale models in a water tank. He found that the narrower the hull, the faster it cut through the water. Yet a single narrow hull was unstable, so Petty opted for two, stabilised with a connecting deck.

Polynesian catamaran canoes used the same principle but had not yet been seen by Westerners. And Petty was the first to apply the concept to a large ship.

His first full-scale catamaran had twin hulls measuring 20 feet long and two feet across. Put through its paces at Dublin in January 1663, it reached a record-breaking 16 knots. Next came Experiment, which reputedly carried 13 men and 10 guns and which, 340 years ago this month, famously raced the Holyhead mailboat.

Sadly, it sank on a subsequent voyage with the loss of all hands, and with it went Petty's hopes of any commercial success.

Petty did make a fortune from his Irish surveys, however, and his mining ventures in Munster (he founded Kenmare as a mining town). He also did well from his Lansdowne and Shelbourne estates. Dublin's Shelbourne Hotel is on the site of his former home at St Stephen's Green.

Today, large high-speed catamarans follow in his wake on the Dublin/Holyhead route, and in 1991 the Irish Nautical Trust built a replica of his catamaran and raced it on the Liffey. The ingenious William Petty would surely have been pleased.

William Petty features in Mary Mulvihill's award-winning book about Irish scientific and inventive heritage, Ingenious Ireland (TownHouse, 2002)