Image of a submarine from a virtual dive trail
Rendered multi-image projection of U-8 on the seabed today. © MSDS Marine
Rendered multi-image projection of U-8 on the seabed today. © MSDS Marine

Protecting the Recent Past for the Future

Submarine wrecks remind us of the importance of the war beneath the sea during the First World War.

For many people the First World War is largely characterised by the static trenches along the Western Front, with the war at sea being largely forgotten save for the big fleet actions like the Battle of Jutland. But fisherman, merchant sailors, aviators and submariners all played their part alongside their naval compatriots in order that Britain and her allies continued to eat and fight on the Western Front. Historic England has sought to ensure that the war at sea was not neglected during the Centenary period by seeking to remember the sacrifices made by those who fought off our coast.

The war under the sea

Of all the methods of naval warfare it is perhaps submarines that capture public imagination the most: we remain fascinated by the technological ability of these silent and deadly killers. Research commissioned by Historic England showed that 44 German U-boats were lost in England’s coastal waters during the First World War. This number represents just over one fifth of all U-boat losses during the war.

British losses

Perhaps unsurprisingly, British submarine losses largely lie further afield, having been lost in operations overseas. Only three are known to have sunk during the war close to our coast: C29 (accidentally mined in the Humber estuary, August 1915), D5 (mined off Great Yarmouth, November 1914) and E6 (mined off Harwich, December 1915).

Assessing the condition of submarine wrecks

While the submarine wrecks were not new discoveries (the locations of many of them are well-known and visited by divers), our work set out to understand for the first time their condition, the extent of their survival and the chemical and physical threats to them. We worked closely with the Ministry of Defence to identify wrecks, such as those of UB-65, sunk off Padstow in 1918, and UB-81, mined off the Isle of Wight in 1917, where there had been a loss of life and where protection as military maritime graves might be appropriate. We also asked researchers and divers to participate by contributing data and information. The increased understanding which resulted from this work provided the first opportunity to inform vital risk management of the submarines, an important benefit given that the wrecks have been on the seabed for 100 years.

The increased understanding provided the first opportunity to inform vital risk management of the submarine wrecks

 As a means to understand the conservation management requirements of the First World War submarines, and metal-hulled ships in general, we also commenced a programme of ultrasonic investigation and analysis (Dunkley 2013). This was prompted by the necessity of understanding the stability of steel hulls of wreck sites so as to identify means of preventing damage and increased degradation.

Of the 44 U-boats identified, we commenced a programme of desk-based assessment, marine geophysical survey and diver-based observations on ten submarines on account of their rarity and group value (U-8, UB-12, UB-17, UB-30, UB-55, UB-75, UB-109, UC-6, UC-46 & UC-70). In addition, the British D5 was included in the study. The project ran through the centenary period and ensured that maritime archaeology contributed to modern historical narratives as a means to connect to the reality of the past.

During the project, two U-boats were identified as having sufficient special interest to warrant investigation for statutory protection: U-8, sunk 4 March 1915, and UC-70, depth-charged 28 August 1918.

The wreck of U-8

The capture and sinking of the German submarine U-8 off Folkestone on 4 March 1915 illustrates an early success of the innovative Dover Barrage, an underwater blockade consisting of minefields laid between Belgium and Dover at the outbreak of war, steel netting anchored to the sea bed and monitoring by surface patrols.

Launched in 1911 as one of four type U-5 boats ordered from the Germania shipyard in Kiel, U-8 was passing westwards through the Dover Strait to attack shipping in the Western Approaches when she ran into the barrage nets. Her attempts to escape attracted the attention of the drifter Robur which called up reinforcements. The destroyer HMS Ghurka lowered an explosive sweep and fired a charge when it snagged on an obstruction believed to be the submarine.

The commander of the severely damaged U-boat, Kapitänleutnant Alfred Stoß, ordered her to surface, where she was abandoned and later sank, though not before HMS Ghurka and HMS Maori had opened fire, hitting the area around the conning tower.

Innovative acoustic survey commissioned by Historic England in August 2015 collected oceanographic data which confirmed that, after being on the seabed for over 100 years, U-8 is lying on an even keel with the height of the conning tower extending some 6m above the seabed (Wessex Archaeology 2015). Her three periscopes and radio masts remain in situ. A build-up of sediment on the western side of the wreck was identified, with possible hull elements having collapsed from their original position onto the seabed.

U-8 was designated a Protected Wreck Site in July 2016 on account of its historical and archaeological importance.

U-8 lies within a wider military landscape as the English Channel was both a transit area and a battlefield for U-boats until August 1918 when the use of new mines and searchlights as part of the Dover Barrage effectively closed the Dover Strait. German surface raiders attacked the Barrage on at least two occasions in actions that have become known as the Battles of Dover Strait (October 1916 and April 1917).

Today, the Strait is extremely busy and congested with shipping, and visiting divers anchoring over the wreck of U-8 would be at risk from passing vessels, particularly if the surface visibility deteriorated. We therefore had to find another means of engagement in order to facilitate access to this important wreck site, and we determined that ‘virtual’ access, by means of an online diver trail, would be an effective way forward.

A digital diver trail brings the U-boat to life for non-divers and the images are a lot easier to interpret than more traditional survey techniques.

  A digital diver trail combines new technologies such as multi-image photogrammetric recording with virtual reality techniques to allow viewers to see a clear 3D image of U-8. Not only does such a trail bring the U-boat to life for non-divers, the images are a lot easier to interpret than more traditional geophysical survey techniques or photographs taken in poor visibility.

The virtual trail for U-8 complements our other trails and was launched online in November 2017. Within its first three months some 6050 new users accessed the site. All of Historic England’s virtual diver trails can be found online.

One twist in the U-8 story concerned the theft of one of its bronze propellers by divers. It was found by police in the Kent area in 2014 and was returned to the German Navy at a ceremony in Portsmouth Naval Base the following year as a symbol of reconciliation and friendship.

The wreck of UC-70

UC-70 was a Type UC II class of coastal mine-laying submarine commissioned into the German Imperial Navy in November 1916. The submarine conducted ten patrols and sank or damaged 40 ships during the war before being bombed and depth-charged off the East Coast on 28 August 1918 with the loss of all hands.

From reports of the initial investigation by Royal Navy divers searching for intelligence material, and the fact that all the hatches were found open at the time of the discovery, it is reasonable to believe that at least part of the crew tried to escape. The bodies of three of the crew, including that of the commander, were recovered by divers in September and October 1918. The divers found no mines in the chutes, so although the activities of UC-70 in the days prior to its sinking are not completely known it seems likely that its mine-laying operations had been successful or that the mines were jettisoned.

Remote sensing and diving investigations in 2016 revealed that UC-70 lies in an upright position with a slight list to port (left). The outer pressure hull of the submarine is corroded away in many places but the 88 Millimetre deck-gun is still intact and in place and the openings of the six mine-laying tubes are visible on the upper surface of the hull. The bow section of the outer hull, forward of the mine-laying tubes, is badly damaged, most likely as a result of depth charges, but the two periscopes are still visible and in situ within their sleeves.

Divers working at an exposed section at the stern observed human remains, comprising the top of an adult cranium and part of the shaft of a humerus or femur, possibly belonging to the same individual. Given their location at the stern of the submarine, these may be those of a torpedo man, stoker or machinist, narrowing down identity to six or seven crewmen. Unusually, a Chinese plate dated to the reign of the Emperor Kangxi (1654 - 1722) was recovered from the submarine's galley in 1993. It is possible that this plate belonged to a crew member who served or had contacts at the German naval base at Tsingtao, China, captured in 1914 and an important Far-East base for the Germans.

If judged only by the numbers of enemy vessels destroyed, the UC II is the most successful submarine design in history. Estimates indicate that they sank more than 1800 enemy vessels. 

Historic England was concerned that parts of the submarine were vulnerable to uncontrolled salvage.

Given that major component parts of the submarine remain in-situ, both internally and externally, and given the presence of skeletal human remains, Historic England was concerned that parts of the submarine, its artefacts and its crew were vulnerable to uncontrolled salvage. On the basis of its historical and archaeological interest, the wreck of UC-70 was protected in August 2017.

In order to ensure that the human remains present on the submarine were not sensationalized, we chose not to develop a diver trail on UC-70. Instead, we encourage responsible diver access. Such access is enabled through the licensing scheme associated with the Protection of Wrecks Act 1973 which applies to all protected wreck sites. 

Licenses are arranged through Historic England.

Managing the past for the future

From 4 August 2014, submerged archaeological remains associated with the First World War, including submarines, began to fall under the aegis of the 2001 UNESCO Convention on the Protection of the Underwater Cultural Heritage. This Convention is intended to enable countries to better protect underwater archaeology by providing a set of rules by which marine archaeological remains can be studied and preserved. As such remains are vulnerable to metal recovery, souvenir and treasure-hunting and the poorly-understood long-term effects of oceanic climate change, the British government has adopted the UNESCO rules as best practice for underwater archaeology.

By following the UNESCO rules, Historic England can ensure that underwater archaeological remains from the First World War continue to be recognised, understood and respected by future generations.

Further information

Dunkley, M 2013 ‘Ultrasonic thickness testing: devising new ways to manage marine heritage’. Research News, Number 19: Spring 2013, 30-31

Wessex Archaeology 2015 U8 Marine Geophysical Survey and Archaeological Report, unpublished report for Historic England

Mark Dunkley

Formerly Marine Archaeologist, Historic England

At time of writing Mark had responsibility for the protection of underwater cultural heritage with Historic England. He has subsequently left the organisation. Mark regularly worked with marine enforcement agencies to detect and prosecute underwater heritage crime and he advises the UK National Commission for UNESCO on marine matters. He is a professional diver and a Fellow of the Society of Antiquaries.