SCARBOROUGH, England (AP) _ A group of young seafarers today said they have calculated where the wreck of 18th century American naval hero John Paul Jones' ship, the Bon Homme Richard, is lying - under a 20th century wreck in the North Sea.

The young explorers, called Sea Cadets, said they pinpointed the Bon Homme Richard's whereabouts using modern sea charts and ancient archives. According to their calculations, the wreck lies about four miles from the Yorkshire coast, under a 4,000-ton merchant ship that sank in 1918.

Derek Haggerston, who organized the Sea Cadets project, said divers were preparing to investigate the site, but that because of drifting and decay, it was unlikely much of the Bon Homme Richard, which was chiefly made of wood, remained to be found.

The 42-gun Bon Homme Richard sank off Flamborough Head, a Yorkshire headland southeast of Scarborough, after a spectacular battle with the 54-gun British frigate Serapis in September 1779.

Thousands of people lined the cliffs to watch the battle, now considered one of the most memorable in naval history.

Over the years there have been several searches for the Bon Homme Richard, many using sophisticated modern equipment including underwater X-ray cameras, but its position was never pinpointed.

Haggerston said his corps used information from shipwreck expert Clive Cussler, who searched but failed to find the Bon Homme Richard in 1979, and old charts provided by the Royal Navy, including one dated 1800 that showed landmarks that have since disappeared.

This allowed the cadets to make accurate bearings that were impossible earlier, he said.

Haggerston said most of the rest of the work consisted of searching through archives, like the court-martial records of the British captains who lost the battle, and a 1901 account of the finding of an 18th-century anchor that was snared in a trawler's fishing nets in nearby Filey Bay.

''One problem is that they didn't use latitudes and longitudes in those days,'' Haggerston said. ''In contemporary descriptions people talked in miles, French miles or leagues,'' and it wasn't always clear which they were using.

Jones was born in Kirkcudbright, Scotland in 1747 but fought for the American revolutionaries against the British in the War of Independence.

His 1779 squadron consisted of the Bon Homme Richard, an old French merchant vessel converted into a warship; a new American frigate, the Alliance; two small French ships and three privateers.

Jones won enduring fame when his squadron intercepted a British fleet returning from the Baltic off Scarborough on Sept. 23, 1779.

The British fleet was under the protection of two British warships, the Serapis and the 20-gun Countess of Scarborough.

Jones engaged the Serapis in battle, and the engagement, which began at sunset, ended more than 3 1/2 hours later by moonlight.

Both ships were heavily damaged. The Serapis, to which Jones lashed the Bon Homme Richard, was set afire in at least 12 different places. The hull of the American warship was pierced, her decks were ripped, her hold was filling with water, and fires were blazing unchecked.

Yet, when the British captain asked Jones if he was ready to surrender, he replied defiantly: ''Sir, I have not yet begun to fight.

When the Serapis surrendered, Jones and his men boarded it while the Bon Homme Richard sank.

After the battle, Jones menaced British shipping as the head of a naval expedition, and returned to America in 1781.

In 1788, he joined the Imperial Russian Navy as a rear admiral, fighting against Turkey, but fell out of favor with the Russians and died in Paris in 1792.

More than a century later, his body was returned to America, where it was buried at the U.S. Naval Academy at Annapolis, Md. The grave has become a shrine to the memory of the man considered to be the father of the American navy.

The Sea Cadets is a nationwide nautical scouting organization for British boys and girls aged 12-16, in which youngsters practice the skills of seamanship.