HMS H5
HMS H5 is a World War One British submarine that lies wrecked on the seabed off the northwest coast of Wales, near the Isle of Anglesey. It is one of the H-class submarines that served in the Royal Navy during the First World War, and its final resting place at these coordinates in the waters of the Irish Sea makes it a site of both historical significance and interest to maritime archaeologists and wreck divers. The H-class submarines were a series of coastal submarines built largely in Canada and the United States and were important assets in the British war effort, particularly for patrol duties around the British Isles. HMS H5 is notable not only as a war grave but also because of the tragic and somewhat unusual circumstances of its sinking.
HMS H5 was lost on 2 March 1918 in a case of friendly fire, a fate that sadly befell several submarines during the war due to the inherent difficulties of identifying submerged or surfacing vessels. The submarine was rammed and sunk by the British merchant vessel Rutherglen in the waters off Anglesey. The entire crew perished in the sinking, making it an official war grave protected under United Kingdom law. The vessel had been commissioned in 1915 and had served throughout much of the war before its untimely end. The loss of HMS H5 was part of a broader pattern of accidents and misidentifications that claimed numerous Allied submarines during both World Wars, and it serves as a poignant reminder of the dangers faced not just from enemy action but from the fog of war itself.
As a seabed wreck, HMS H5 lies at a depth that brings it within reach of experienced recreational divers, though it must be approached with the full understanding that it is a protected war grave. The wreck retains much of its form on the seabed, as submarine hulls tend to be more robust structures than surface ships. Divers who have visited the site report the eerie and solemn atmosphere characteristic of submarine wrecks — the compressed, cylindrical hull partially silted into the seabed, encrusted with marine growth, and inhabited by the various fish and invertebrates that colonise such artificial reefs over time. The visibility and conditions in the Irish Sea can vary considerably, and the site demands respect both as a matter of safety and of reverence for the men who died there.
The surrounding area is the Irish Sea off the northwest coast of Anglesey, one of the most historically and naturally rich coastlines in Wales. Anglesey itself, known in Welsh as Ynys Môn, is a large island separated from the mainland of north Wales by the Menai Strait. The coastline near the wreck's coordinates is characterised by open sea views, tidal currents, and the distant profiles of the Snowdonia mountains visible from the shore on clear days. The island has an extraordinarily rich heritage including prehistoric monuments, medieval castles, and a strong seafaring tradition that makes the presence of a wartime wreck in its waters feel deeply connected to the broader sweep of local history.
Visiting the wreck requires a boat, as it lies offshore and is not accessible from land. Dive charter boats operate from ports around Anglesey and the north Wales coast, including Holyhead, which is the main ferry port on the island and has good facilities for maritime activities. The site is designated as a Protected Place under the Protection of Military Remains Act 1986, which means that diving to observe is permitted, but any interference with, disturbance of, or recovery of artefacts from the wreck is strictly prohibited and a criminal offence. Divers should notify the relevant authorities and ensure they have appropriate qualifications and experience for Irish Sea conditions, which can include strong tidal streams, reduced visibility, and cold water temperatures year round.
One of the more poignant and fascinating aspects of HMS H5's story is that its crew have no known graves other than the wreck itself, which in law and in spirit serves as their tomb. The submarine carries the bodies of its sailors within the hull, and this gives the site a gravity that goes beyond its interest as a historical or recreational dive. The Royal Navy and the Commonwealth War Graves Commission recognise the men who died aboard her, and there are memorials to them on land as well as the implicit memorial of the wreck itself beneath the Irish Sea. The story of HMS H5 is one that connects the visitor — whether approaching by boat above the site or reading about it on dry land — to the very human cost of submarine warfare in the First World War.