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Other Historic Assets

Coastal and maritime archaeology

In this guide

1. Managing the Marine Historic Environment of Wales

Britain is an island nation and our shores have long been the points of contact with the outside world. Trade, invasion and defence, exploration, settlement, leisure and industry have all left distinctive marks on the shores and in the seas of Britain. Wales is certainly no exception.

This maritime heritage is a valuable resource and all evidence can be used to tell the stories of our connections with the sea. Shipwrecks and hulks are obvious sources of information, and objects, harbours, buildings and structures are also important in building a picture of our past.

There are other, more unexpected, stories to be found in and next to the sea. The boundary between land and sea changes over time. Today’s coastline is radically different from the coast which our prehistoric ancestors would have known and exploited thousands of years ago. We can sometimes see traces of their landscapes, parts of the land they would have known can now only be glimpsed in the intertidal zone or through innovative programmes of seabed mapping.

Cadw has an important role to play in protecting our maritime heritage. We can legally protect important sites through designating them as scheduled ancient monuments and we can also give legal protection to the most significant wrecks by designating them under the 1973 Protection of Wrecks Act. We also work with the Marine Consents Unit to ensure that the protection of maritime heritage is taken into account during developments.

The main source of information about wrecks and all aspects of our underwater heritage is the marine database of the National Monument Record compiled by the Royal Commission on Ancient and Historical Monuments in Wales with whom Cadw works closely to ensure records and surveys are comprehensive and reach the widest possible audience.

Managing the Marine Historic Environment of Wales explains the Welsh Government’s approach to the marine historic environment and offers best-practice guidance for its protection and management.

It explains the different types of evidence available to identify past human activity in and by the sea. It outlines the threats to this evidence and how these can be managed sustainably. It sets out the broad legislative framework that affects underwater heritage in Wales and identifies the responsibilities and approach of Cadw, the Welsh Government’s historic environment service, in the decision-making process.

It contains practical guidance for all those concerned with underwater activities. Whilst it is aimed at public authorities and sea users, it will also be of interest to anyone who wants to learn more about archaeological evidence preserved under the sea or on the seashore of Wales.

2. 'Wrecks' and 'Wreck'


The seas around Wales are littered with the wrecks of vessels of all shapes and sizes. Although all of them have historic value, six currently have legal protection. These six are known as ‘designated wrecks’ and are protected under the 1973 Protection of Wrecks Act. Any activities on these wrecks, including visiting, filming and surveying, require a licence, granted by Cadw. Different licences cover different activities. Forms and background notes can be downloaded from our site or you can contact Cadw for advice.

Divers who discover a historic wreck should take great care not to damage it; either by disturbing the structure or by removing artefacts from the wreck. Cadw is always interested to hear about discoveries and we may be able to help find out more about the site.


‘Wreck’ is the term used to describe something which has been lost at sea. ‘Wreck’ can be something which fell overboard, something which was thrown overboard to lighten the ship, or a piece of the ship itself. In fact, ‘wreck’ can be almost anything!

All wreck material, whether it is recovered at sea or on the shore, by law must be reported to the Receiver of Wreck. The types of material reported include portholes, bells, compasses, pots, cannon, coins, nameplates …the list goes on. Reporting wreck does not automatically mean that it will be taken away from you, but it means that the historic and archaeological value of the material can be assessed and the Receiver of Wreck will, if possible, try and trace the owner.




3. Wrecks of Wales

The Smalls Viking Wreck Site, Pembrokeshire (SM 4644 0876)

The findspot of an important Viking sword guard of 11th century date, on the trade route between Viking Dublin and Denmark, 25km(15 miles) off shore.
Protected Area: 100m radius, centre 51 43.18’N 05 40.13’W

The Mary, Skerries, Anglesey (SH 2651 9479)

The ‘first British yacht’, built by the Dutch East India Company and given to King Charles II on his restoration. Samuel Pepys sailed in her, and she was used for official journeys and for royal leisure trips. Sunk in 1675, she has been partially excavated and artefacts are in Liverpool Museum. Protected Area: 100m radius, centre 53 25’16”N 04 36’40”W

Pwll Fanog Wreck, Menai Strait, Anglesey (SH 5342 7070)

A slate carrying cargo vessel from around 14th or 15th century. The slates were from the Llanberis area, split with a gouge and stacked into the wooden vessel which survives beneath its heavy cargo. This gives important information about the North Wales slate industry in late medieval periods.
Protected Area 150m radius, centre 53 12’46”N 04 11’43”W

Tal y Bont Wreck, Barmouth, Gwynedd (SH 5665 2229)

A merchant vessel with a cargo of Carerra marble from Italy, sunk around 1702. Well armed with 18 main battery, 8 smaller cast iron and 10 wrought iron guns, the wreck has been partially excavated to reveal her bell, and a multitude of navigational and domestic artefacts. Sunk on the treacherous Sarn Badrig.
Protected Area 300m radius, centre 52º 46’ 41” N 04º 07’ 24” W

The Diamond, Barmouth, Gwynedd (SH 5276 2291)

A 19th-century composite wreck built of wood with copper sheathing, but with iron strengthening to the frame, with two large water tanks. The recently discovered ship (close to the Tal y Bont wreck) is unexcavated, so her cargo and form and even her identity is uncertain. Survey and research into this vessel is being undertaken.
Protected Area 200m radius, centre 52 46.531’N 04 11.025’W

Resurgam Submarine, Rhyl, Denbighshire (Beyond conversion to NGR)

The world’s earliest extant powered submarine, Resurgam was designed by Rev Garrett in 1879 and built by J. T. Cochrane in Birkenhead (where a model can be seen in the docks). She had a cylindrical hull with cone shaped bow and stern and was powered by a large boiler and Lamm-type engine. She sank 15 miles off Rhyl on the way to Portsmouth for naval trials.
Protected Area 300m radius, centre 53 23.78’N 03 33.18’W

4. Submerged landscapes

Climate change and global warming are current issues, but other humans — our earliest ancestors — have also had to witness dramatic changes in their environment. Four Ice Ages are known to have occurred during the Palaeolithic period, between approximately 800,000–12,000 years ago. Between these Ice Ages were warmer periods. During the last Ice Age the cold temperatures and extensive ice sheets made much of Northern Europe uninhabitable. As temperatures rose and the glaciers melted around 12,000 years ago, people began to spread north and west. However, with the melting glaciers came rising sea levels. Fertile lowlands were inundated, turning woodland to salt marsh and pushing coastlines back towards higher ground. At times a slow and insidious process, at times dramatically fast, the loss of familiar landscapes occurred within the memory of living generations.

These lost lands off the coast of modern Britain can now be re-visited due to innovative work by the University of Birmingham. They have used survey data collected by commercial companies to map the seabed, and explore what these prehistoric lands may have looked like.

These landscapes cannot be seen in detail, but key features can be mapped. We can see, for example, where 12,000-year old river courses emptied into a substantial lake in what is now the Bristol Channel. Low-lying areas around the lake would have provided hunters with rich prey and may contain valuable archaeological remains. This kind of information is fed into the planning process, helping to make sure that heritage is protected.

The West Coast Palaeo-landscapes Project was funded by the Aggregates Levy Sustainability Fund administered by English Heritage and the Welsh Government and also received funding from Cadw.

5. Sources of information

To find out more about the marine historic environment, then the resources below should be able to help.

For information about designated wrecks and types of licence available:

For the Welsh Historic Environment Record, including information about coastal and intertidal archaeological sites and searchable maps:

For information about the national maritime archaeology database, including records of aircraft losses, shipwrecks and maritime features:

For general information about underwater archaeology and up-coming courses:

6. Get involved

Cadw works with the Nautical Archaeology Society (NAS) to provide training and courses for people in Wales who want to find out more about our maritime heritage. Some courses are suitable for complete beginners, and others require some former knowledge. Courses are available for divers and non-divers!

The NAS also run the ‘Adopt a Wreck’ scheme. If you, or your group, regularly dive the same wreck sites then why not ‘adopt’ them? You could play an important part in monitoring the condition of your wreck, as well as helping to find out much more about it.

Cadw has also grant aided the Welsh Archaeological Trusts to set up and run a project called ‘Arfordir’. Meaning ‘coastline’ in Welsh, the ‘Arfordir’ project aims to get individuals and groups involved in recording, researching and monitoring coastal archaeological sites in their area.

Clwyd-Powys Archaeological Trust

Dyfed Archaeological Trust

Glamorgan-Gwent Archaeological Trust

Gwynedd Archaeological Trust

Arfordir Coastal Heritage