Beaufort’s Dyke is a deep underwater trench in the North Channel of the Irish Sea, stretching over 50 kilometers between Scotland and Northern Ireland.

Historically used as a dumping ground for military ordnance post-World War II, it now presents significant environmental and safety concerns.


The Formation Of Beaufort’s Dyke

The physical characteristics of Beaufort’s Dyke are quite remarkable. Stretching over 50 kilometers in length and reaching widths of up to 3.5 kilometers, it’s a significant underwater canyon in the Irish Sea. Its depth, exceeding 200 meters in some places, makes it the deepest part of the North Channel.

Read More Truk Lagoon – The Biggest Graveyard Of Ships In The World

The formation of Beaufort’s Dyke is deeply rooted in the Earth’s geological history, specifically in the processes associated with the last Ice Age. During this period, glaciers advanced and retreated over what is now the North Channel between Scotland and Northern Ireland. The immense pressure and movement of these glaciers played a critical role in sculpting the seabed, carving out deep trenches and valleys. Beaufort’s Dyke, as the deepest of these formations, is a testament to these powerful natural forces.

The red mark indicates the location and size of Beaufort’s Dyke. Image by NordNordWest CC BY-SA 3.0

The retreat of the glaciers at the end of the Ice Age further shaped the Dyke. Melting ice led to the release of vast amounts of water, which flowed through and over the already formed trench, further deepening and widening it. This process left behind a unique topographical feature – a deep, narrow trench that stands out in the otherwise relatively shallow waters of the surrounding sea.

Maritime History

Beaufort’s Dyke has played a significant role in the maritime history of the British Isles. Its strategic location as a deep channel in the North Channel between Scotland and Northern Ireland has made it a crucial passage for ships for centuries. This natural deep-water trench provided a safer and more navigable route for vessels, especially larger ships that could not traverse shallower waters. As a result, it became a favored passage for maritime traffic, including commercial trade and military movements. This importance is reflected in historical records and maps, where Beaufort’s Dyke often features as a key maritime landmark.

Read More Germany Built A Weather Station In Canada During WWII

The Dyke’s role in maritime history is not just limited to navigation. The surrounding areas have been the site of numerous historical events, including naval battles and skirmishes, particularly during periods of conflict in European history.

The military history of Beaufort’s Dyke is particularly notable during the World War II era. Its strategic location made it a focal point for naval operations in the North Channel, serving both as a defense point and a route for military vessels. However, the end of World War II marked a different and more controversial chapter in the Dyke’s history.

After the war, Beaufort’s Dyke was used extensively by the British government as a dumping ground for surplus military munitions. This decision was driven by the immediate need to dispose of large quantities of ordnance in a post-war environment.

The Dyke’s depth and remote location made it seem like an ideal place for such disposal. It is estimated that over a million tons of military debris, including conventional explosives and chemical weapons, were dumped into the Dyke.

A map from 1947 showing the munitions dumping ground.

Also, documents from the Public Record Office reveal that during the 1950s, around two tonnes of metal drums, encased in concrete and containing radioactive laboratory waste and luminous paint, were disposed of in Beaufort’s Dyke.

This has left a legacy that continues to raise environmental and safety concerns in the present day.


One of the most pressing concerns regarding Beaufort’s Dyke is the environmental impact of the extensive dumping of military ordnance that occurred post-World War II. This ordnance includes a wide range of munitions, from conventional explosives to chemical weapons.

Read More Three U-Boats Missing Until 1985, Now Under a Car Park

Over time, the casings and containers of these munitions have begun to corrode, raising significant worries about the leakage of toxic substances into the marine environment. The potential release of such hazardous materials poses a serious threat to the marine ecosystem, potentially affecting a wide range of marine life, from the smallest organisms to larger mammals, and disrupting the delicate ecological balance of the region.

More worryingly, phosphorous bombs washed up in Scotland in 1995, and anti-tank grenades have been found more recently. There was even a 2.5 Richter earthquake measured in the Dyke in 1986!

The presence of the munitions dump has also hampered ideas of building a crossing from Scotland to Northern Ireland. Advisers report that the construction of a bridge in the area is too risky.