Sailing regattas had been held in Caernarfon as early as 1829 and again in 1846, regular enough to suggest a sailing fraternity that wanted formal organisation. In 1847 a group of prominent locals - the solicitor Llewellyn Turner, William Knight (Rear-Commodore of the Royal Harwich Yacht Club), Lord George Douglas-Pennant of Penrhyn, and others - formed the Royal Welsh Yacht Club. On 5 May that year the club was awarded the warrant to fly the defaced Blue Ensign, the badge of distinction granted to certain yacht clubs by the Admiralty. Three days later, Queen Adelaide - widow of King William IV, then living in retirement - bestowed her royal patronage on the new club. Robert Stephenson was the first vice-commodore, with Turner himself as rear-commodore.

The membership rolls have included some quietly remarkable people. Robert Stephenson, the club's first vice-commodore, was the engineer behind the Britannia Bridge - the wrought-iron tubular railway bridge across the Menai Strait completed in 1850 - one of the most ambitious civil engineering projects of its century. Thomas Assheton Smith, also a vice-commodore, owned the schooner Titania, which competed in the 1851 America's Cup at Cowes (then known as the 100 Guineas Cup), the race that began the longest-running trophy contest in international sport. Lionel Rees - another member - sailed single-handedly across the Atlantic from Wales to Nassau in 1933 in a ketch, for which the Cruising Club of America awarded him the prestigious Blue Water Medal in 1934. The club's notable members tend to share a quiet relationship with very large bodies of water.

The clubhouse is the headline. Porth yr Aur was one of two water-gates set into the late 13th-century town walls Edward I built alongside Caernarfon Castle - the other was Porth yr Marl, no longer standing. The Golden Gate was a working harbour-side entry, with a postern above and a portcullis below; it took its name supposedly from a hoard of golden trinkets reputedly buried within. By the time the RWYC took it over in the mid-19th century, the tower had passed through many uses and many owners. Members converted it into a clubhouse, and it has been one continuously ever since - making this very probably the oldest building still in service as a yacht club anywhere in the world. The view from the upper rooms is of the Menai Strait, with the Snowdonia mountains rising beyond on a clear day.

The club today is small by world standards - 301 members as of April 2023, up from 260 the year before - but actively sailing. The Menai Strait remains a challenging cruising ground: tidal, narrow in places, with the notorious Swellies between the Menai and Britannia bridges where currents reach six knots on springs. Members run cruises, race weekends, and offshore passages out through the Caernarfon Bar and into the Irish Sea. Most yacht clubs see themselves as part of a tradition. Few of them get to anchor that tradition quite this literally - in stones laid in the 1280s, on a wall built to keep Edward's enemies out of a town his architects called the most beautiful in Christendom, with the same water still moving past the same gate.