When the steamship Leeds struck Harry Furlong Rocks, the Cemlyn lifeboat launched into rising seas. By the time the boat reached the wreck, a second steamship, Commerce, had also come up and was taking off most of the passengers in her own boats. One small boat, however, had drifted clear and could neither reach land nor regain Commerce. The Cemlyn crew rowed across, took on the three men aboard, and brought them home. Coxswain Owen Lloyd Williams was awarded the silver medal of the Royal National Institution for the Preservation of Life from Shipwreck for this service. In December 1845 the barque Frankland, on passage from Bahia to Liverpool, was wrecked at Cemaes Bay; three more Cemlyn crewmen - Robert Griffiths, Richard Owen and Owen Highland - earned silver medals for rescuing the 18 men aboard.

The original boat served until 1853. A series of replacements followed - some new builds, some transfers from other Welsh stations. The Sophia, a 30-foot self-righting boat, arrived in 1865 and stayed until the station was first closed. The naming of the lifeboats often reflected their donors: Good Shepherd, paid for in 1877 by the Loyal Order of Ancient Shepherds (Ashton Unity), was renamed B. J. Nicholson in 1890 after a new benefactor. Annie Collin came over from another station in 1904. Sir John, the last lifeboat at Cemlyn, served the final five years, also transferred in from elsewhere. Cemlyn's location made it perennially difficult: a remote shingle beach with no protected boathouse approach, far from where most able seamen actually lived.

By 1872, raising a crew at Cemlyn had become impossible - the men were not living close enough to launch in a hurry, and the RNLI decided to close the station and open a new one at Cemaes a few miles east. The Cemlyn boathouse stood empty for five years. Then enough experienced seamen returned to the village that a request to reopen was approved, a new boathouse was built, and a 32-foot lifeboat - the Good Shepherd - arrived in October 1877. The station ran for another 42 years. Finally, on 13 March 1919, after the slow decline that affected most coastal stations as bigger motor lifeboats took over their work, the second closure of Cemlyn was permanent.

In 1978, on the 150th anniversary of the original Cemlyn station - and of the founding of the Anglesey Association for the Preservation of Life from Shipwreck - a memorial was erected near the site of the boathouse. It commemorates the first Anglesey lifeboat station and the two people who built it: the Reverend James Williams and his wife Frances, who refused to let what they had watched from the cliffs in 1823 simply be repeated. Williams died in 1872. Frances died before him. The Association they founded merged into the RNLI in 1855, contributing to the institution that today runs the Holyhead and Moelfre stations covering the same coast. The Cemlyn boathouse is gone, but the lagoon and the shingle ridge it stood beside are now the most important breeding site for Sandwich terns in Wales.