Mary was built for showing off. Her counter was carved and gilded, her interior fitted out for a sovereign who had spent his exile dreaming of comfort. Samuel Pepys mentions her in his diary, alongside the other royal vessels Charles raced for sport on the Thames. But Charles was a restless owner. Within a year he had commissioned a faster boat, the Katherine, built for him by Phineas Pett of the great Pett shipbuilding dynasty. Mary was demoted from royal plaything to working transport, ferrying diplomats, civil servants, and the slow business of empire back and forth across the Irish Sea between Dublin and Holyhead. For fifteen years she did this without incident, an elegant Dutch yacht hauling government correspondence between two capitals that had not yet learned to trust each other.

On 25 March 1675, Mary was running eastbound from Dublin to Chester with twenty-eight crew and forty-six passengers aboard. Sometime before dawn, fog closed in over the southwest corner of the Skerries, a low cluster of reefs off the northern tip of Anglesey. She struck. The hull, never built for the open sea pounding she now took, broke up quickly. Thirty-five of the seventy-four aboard were killed. Thirty-nine somehow reached the bare rocks of the Skerries themselves and waited, soaked and exposed in the March cold, for two days before anyone came for them. The first royal yacht of the Royal Navy was gone, scattered across a tidal shoal that would not give her up again for almost three hundred years.

Mary lay forgotten until July 1971, when two amateur diving clubs found her independently and within weeks of each other. The Chorley Sub Aqua Club and the Merseyside Sub Aqua Club had both been working the Skerries when their members started bringing up bronze cannons cast with the royal cypher. The discovery was sensational and immediately dangerous. As word spread, looters arrived. Under the direction of Peter Davies of Liverpool University, working with the Merseyside Museums, archaeologists raced to recover what they could before the site was stripped. The collection that survived now numbers over 1,500 objects, including cutlery, jewellery, and personal possessions of the people who drowned. The Merseyside Museums display a model of Mary built by Des Newton alongside the relics, a small reconstruction of what was lost and what was found.

Mary's looting helped force a change in British law. The Protection of Wrecks Act, passed in 1973, gave the government power to designate historically important wreck sites and prosecute anyone disturbing them. When the first designations went out in January 1974, Mary was on the list - the second site protected under the new law, after the Cattewater Wreck near Plymouth. She is still monitored today, half a century later, by a licensee and by contractors working for the Act. The wreck of a small Dutch yacht given to a king as a diplomatic gesture has become the legal precedent that protects every other historic shipwreck in British waters - a quiet bureaucratic legacy for a vessel that survived only fifteen years afloat.