Underwater Archaeology

The Nautical Archaeology Society also publishes The International Journal of Nautical Archaeology with Blackwell Publishing, a new series of monograph reports and a members’ newsletter, Nautical Archaeology. It runs several public participation projects.


List of Figures

The Dover bronze-age boat
The fifteenth-century Newport ship
Experimental archaeology: building a replica log boat
Trials of the Loch Glashan replica log boat
Post-fieldwork activity
Archaeological sites as part of a settlement pattern
Survival of clues on underwater sites relative to dry sites
An RNLI wreck chart for 1876-7
Site types: aerial photograph of a stone- built fish-trap at Airds Bay, Scotland
Tree-rings viewed through a microscope
Tree-ring sequence built up from trees in the same area
Typology: how it works
Stratigraphy from above: the sequence of events
Stratigraphy: what it can reveal
The importance of context and stratigraphy
Site-formation processes
Re-used ship’s timbers in an open barn on the Turks and Caicos Islands
In situ recording: a diver’s recording form completed during excavation of the Mary Rose in 1982
Planning contexts
Harris matrix
Section through a gully on the wreck of El Gran Grifon (1588)
An archaeological database
An eighteenth-century gravestone near the River Tay in Perthshire showing a salmon fisherman’s square-sterned coble
A diver sketching a late ninetenth-century shipwreck in Dor, Israel
A simple set-up for photographing finds using a vertical stand
A vertically photographed wooden weavin heddle from the Armada wreck La Trinidad Valencera (1588)
Obliquely photographed wooden bellows from the Armada wreck La Trinidad Valencera (1588)
Important considerations for successful underwater photography
A 5 metre square photomosaic of ship remains on the Duart Point wreck
A photographic tower positioned on a rigid site grid
Photomosaics: formula to calculate lens focal length and camera height necessary to give the required coverage
Underwater use of a video camera
The earth, showing latitude, longitude and equator
The basis of the Universal Transverse Mercator (UTM) projection
A scatter of shots showing precision and accuracy
Taking horizontal sextant angles
How to use sextant angles (scribed on drafting film)
Sextant angles: plotted geometrically from baselines between charted features
A triangle of error, or ‘cocked hat’
The use of coastal features as transit marks to establish the position of a site
Accuracy of transits
Temporary transits formed by setting up paired ranging rods along a shore baseline
Surveying a submerged site in shallow watei using a shore-based EDM
Differential GPS system with satellites, shore-based reference stations and in-boat mobile receiver
Towed diver search
Swimline (freeline) search
The offset method in use (with metal detector)
Jackstay (corridor) search
Circular search
500 kHz sidescan sonar image of a v-shaped fish-trap from the River Barrow, County Wexford, Ireland
Sidescan sonar image of the SS Storaa (1943)
Chirp and Boomer image from Strangford Lough, Northern Ireland
A two-dimensional profile and interpolated timeslice of the Grace Dieu (1439) wreck, River Hamble, Hampshire, UK
Geophysics equipment: 1) magnetometer, 2) sidescan sonar, 3) sub-bottom profiler, 4) ROV
Excavation plan of part of the Spanish Armada wreck La Trinidad Valencera (1588)
Representing the sea-bed using symbols
Radial method of survey
Recording the profile of a wreck using vertical offsets from a horizontal datum
Offset method, including plotting results
Ties/trilateration: survey and drawing up results
The principle of levelling to establish relative heights/depths
Depth relative to a temporary benchmark
A simple clinometer
A double-strung planning frame
A diver taking DSM measurements
Braced quadrilateral (3-D survey)
Joining quads (3-D survey)
Measuring between quads (3-D survey)
Good control-point network shapes (3-D survey)
Secondary points (3-D survey)
Poor control-point network shapes (3-D survey)
Positioning detail points on features using control points (3-D survey)
Surveying a submerged site in shallow water using a shore-based ‘total station’
Excavation strategies: trench and test pits
Probing to record sediment depths and obstructions
Use of air or water probes
Optimum place for tree-ring sampling
Taking a spot sample
Column or monolith sampling from a section
Excavating a wooden weaving heddle on the Armada wreck La Trinidad Valencera (1588)
Excavation tools: the trowel and the paint brush
A conservator removing the surviving section of a gunpowder barrel, excavated from the Spanish Armada wreck La Trinidad Valencera (1588)
Excavation using airlift
Water-dredge operation
Teredo navalis (shipworm)
A concretion recovered from the Duart Point wreck (1653) site, Mull, Scotland
An X-ray of the concretion shown in figure
The Duart Point sword hilt shown in and after conservation
Excavating a small fragile object - a leath water-bottle - from the Armada wreck La Trinidad Valencera (1588)
Raising a large organic object - a spoked wooden wheel - from the Armada wreck La Trinidad Valencera (1588)
The leather water-bottle shown in is brought to the surface and handed to the waiting conservator
A pocket sundial with integrated compass found on the wreck of the Kennemerland (1664)
A covering of sandbags placed over a fragile area on the Duart Point (1653) wreck, Mull, Scotland
Archaeological illustration in practice
Recording shape: tracing round an object with a set-square and pencil
Recording shape by establishing a vertical datum and taking offset measurements
A radius template in use
A radius chart in use
Correct orientation of a pottery sherd when using a radius chart
A simple pottery drawing
Thickness-gauge callipers in use
Archaeological illustration of a jug complete with spout
Profile gauge in use
Depiction of complex decoration (‘rolled out’)
The drawing of a complex object - swivel gun from La Trinidad Valencera (1588), with views and details selected to convey the maximum amount of information
Illustration of two pairs of brass dividers from the Dartmouth (1690)
Drawing of a more complex pot
Drawing of a boatbuilder’s tar brush from western Scotland
A render of the 3-D laser-scan data of the figurehead from HMS Colossus (1798)
An orthographic view of the shaded 3-D laser-scan data of the Mary Rose (1545) hull
A plan chest for the storage of plans and drawings
An example of a site-location map
Interpreted and ‘naturalistic’ representations of the same section prepared for publication
Representing topography with hachures and contours
One of the Mary Rose Trust organic stores
The Mary Rose card file system
A public talk during a NAS project at Stourhead, Wiltshire, UK
A team member being interviewed for television during work on the Mary Rose (1545) site
Anchor terminology
Cast ordnance: terminology - a corresponding recording form is available on the NAS website
Wrought-iron breech-loading tube gun: terminology - a corresponding recording form is available on the NAS website
Breech-loading swivel-gun: terminology - a corresponding recording form is available on the NAS website
A small swivel-gun recovered from a Spanish Armada wreck off Streedagh Strand, Ireland
Plan and side view of a decorated cast- bronze gun from the Spanish Armada wreck La Trinidad Valencera (1588)
A Tudor rose heraldic emblem from one of the bronze guns from the Mary Rose (1545)
The weight number on the breeching ring reinforce on the Stirling Castle’s (1703) demi-cannon, as shown in figure
Founder’s mark (Thomas Western), touch-hole and details of markings on the first reinforce on the Stirling Castle’s (1703) demi-cannon, as shown in figure
Detail of the broad arrow on the Stirling Castle’s (1703) demi-cannon, as seen in figure
Plain iron guns from the Armada wreck El Gran Grifon (1588)
A drawing properly set out for publication of a piece of ordnance - a cannon ferrier from a Spanish Armada Wreck off Streedagh Strand, Ireland
Rubbing taken from the top of the barrel of the swivel-gun shown in figure
A demi-cannon from the wreck of the Stirling Castle (1703)

List of Plates

Charles Deane diving on HMS Royal George (1782)
Ethnographic recording of a three-log kat in Edava, Kerala, India
NAS Training project near Bristol, UK
More archaeology on the foreshore in the UK with NAS Training
A diver examining a chest of longbows on the Mary Rose (1545)
Site types: reconstruction of a crannog on Loch Tay, Scotland
The Swedish man-of-war Vasa (1628)
Archaeological team on hookah preparing to dive
A commercial archaeological diving unit working to UK Health and Safety Executive protocols for surface-supplied diving
Recording timbers: 1:1 tracing of timber surfaces on polythene
Stratigraphy: an underwater excavation face showing several stratagraphic layers
Recording in situ: a slipware bowl during excavation on the Duart Point wreck (1653), Mull, Scotland
On-site finds processing
Free-standing photographic tower in use within a survey grid to record a photomosaic
A ‘total station’ ready for use
A dry run practice of a swimline (freeline) search
High-definition multibeam sonar point cloud image of the 203 m (660 ft) long wreck of HMS Royal Oak (1939) in Scapa Flow, Orkney
Surface rendered multibeam sonar image of rock gullies off Moor Sand, UK, containing bronze-age and seventeen-century material
Multibeam sonar image of the SS Storaa (1943)
Multibeam image of a prehistoric land surface at the base of the 8 m (26 ft) high underwater Bouldner Cliff in the Solent, UK. The wreck of the 44 m (143 ft) long dredger Margaret Smith (1978) is included for scale
High quality, diver-recorded site-plan of the Hazardous (1706) wreck-site
Multibeam sonar image of the Hazardous (1706) wreck-site for comparison with plate
Multibeam image from a single pass in 2002 showing the sea-bed around the wreck of the Stirling Castle (1703)
Multibeam image from a single pass in 2005 showing the sea-bed around the wreck of the Stirling Castle 3 years after the pass shown in plate
Multibeam image of a nineteenth-century wooden sailing ship on the Goodwin Sands
Ground discrimination data collected from a single-beam echo-sounder showing bathymetry, hardness and roughness of the wreck of the 178 m (580 ft) long Markgraff (1919) in Scapa Flow
Three-dimensional plot of magnetic data acquired from the La Surveillante (1797) wreck-site in Bantry Bay
Photograph showing a Geometrics G-881 caesium magnetometer, an EdgeTech 272-TD side-scan, a GeoAcoustics side-scan and an Imagenex 885 side-scan sonar
Using vertical offsets to record hull profile
Underwater survey: diver with drawing board
A clinometer in use
A double-strung drawing/planning frame in use
Drawing/planning frames being used vertically to record vessel remains on the foreshore
A screen-shot showing Site Recorder in use on the Mary Rose (1545) site
Underwater excavation with an airlift
Excavating with a water-dredge in less than 5 m (16 ft) of water in Dor, Israel
Underwater excavation with a water-dredge
The effects of uncontrolled drying of organic material - samples of oak from the Mary Rose (1545)
A gun carriage is lowered into a temporary polythene-lined tank pending dispatch Q to the conservation laboratory
The base of a wooden gun carriage being prepared for lifting
A batch of objects being prepared for transport to the laboratory
A current gauge on the Duart Point (1653) wreck, Mull, Scotland
Monitoring of the underwater environment on the Mary Rose (1545) wreck using an RBR data-logger
Oak blocks placed on the Mary Rose wreck-site to study the activity of marine wood-boring animals
A conservator attaches an aluminium anode to an iron gun on the Duart Point (1653) wreck, Mull, Scotland
Public outreach: children learning about underwater archaeology
Opportunities for publishing archaeological work, both electronically and in hard copy
A one-hole stone anchor found at Chapman’s Pool, Dorset, UK
A two-hole stone anchor found near Golden Cap, Dorset, UK
Divers practise underwater survey techniques during a NAS Part I course
Obtaining samples for dendrochronological dating during a NAS Part III course
Excavation and survey during a NAS Training project on the foreshore near Bristol, UK


The Nautical Archaeological Society has for many years been a champion of best practice in archaeology under water through its internationally acclaimed training scheme, the International Journal of Nautical Archaeology, and a wide range of practical outreach projects. The original edition of the NAS Handbook was another invaluable and much-appreciated part of how the Society has supported practical involvement in nautical archaeology. Ever since it went out of print some years ago, there have been continual enquiries about when a reprint or new edition would be available.

It is therefore with great pleasure that I introduce this new edition of an invaluable publication. The whole text and most of the illustrations have been comprehensively revised and updated, and, as explained in the introductory first chapter, there are several entirely new sections on vitally important aspects of the subject. In many respects, as the new title indicates, this is as much a new publication as a revision, and it will be all the more valuable as a result.

To users of the first NAS Handbook, this second edition may have seemed a long time coming, but it has involved a huge amount of work by a large number of contributors who have very generously provided their expertise on a voluntary basis. I am sure that every reader will wish to thank them all for sharing their wisdom and experience. Our Vice-President, Colin Martin, has been very generous in providing a very large number of the images and we are also very grateful to Graham Scott for the majority of the line illustrations, which have intentionally copied or been inspired by Ben Ferrari’s drawings in the original book. We are also grateful to all the other photographers and illustrators whose work is acknowledged.

This publication would not have come to fruition without the very patient and dedicated work of our editor, Amanda Bowens, who has shown great tact, persistence and skill in marshalling all this material. We are also grateful to Paula Martin for editorial assistance and compiling the index. Finally I would like to pay tribute to Lucy Blue and the rest of the NAS Publications Sub-committee for pushing the project ahead, and to Wiley-Blackwell, our very supportive publisher, who have been responsible for the design and production.

I am sure everyone who uses this book, whether in an academic, professional or a vocational context, will benefit from developing their interest and skills in nautical archaeology, thereby enhancing the quality of the work they do. If it is as successful as the original NAS Handbook, it may not be so many years before a further reprint or new edition is needed, so any comments and suggestions will always be gratefully received. In the meantime, may your explorations in nautical archaeology be a constructive and rewarding experience.

George Lambrick
Chair NAS


Except where otherwise stated, the drawings in this second edition are by Graham Scott, copied or inspired by Ben Ferrari’s drawings in the first edition.

Contributors to the second edition

Jonathan Adams, BA DPhil FSA MIFA

Marc-André Bernier, BA MA

Lucy Blue, BA DPhil

Amanda Bowens, BA MA

Martin Dean, BSc MIFA (Hon) FSA

Justin Dix, BSc PhD

Joe Flatman, MA PhD PIFA

Craig Forrest, B.Comm LLB LLM PGCE PhD

Damian Goodburn, BA PhD AIFA

Alexzandra Hildred, BA MIFA FSA

Peter Holt

Kester Keighley, MSc Stuart Leather, MSc Gordon Le Pard, BSc

Colin Martin, PhD FRHistS FSA Scot MIFA MAAIS

Paula Martin, BA Dip Class Arch PhD FSA Scot MIFA

Douglas McElvogue, PhD MIFA FSA Scot

Sean McGrail, FSA MA PhD DSc MIFA Master Mariner

Gustav Milne, MPhil FSA

David Parham, BA MSc MIFA RPA

Leslie Perkins McKewan, MSc PIFA

Rory Quinn, PhD

Julie Satchell, BA MA MIFA

Graham Scott, AIFA

Amanda Sutherland, BSc ACR

Christopher Underwood, BEd MA

Steve Waring, BSc

Michael Williams, LLB

The editor is extremely grateful to the following for their help and support:

Mark Beattie-Edwards

Lucy Blue

Alan Bowens

Alistair Carty

Rebecca Causer

Alison Hamer

Mary Harvey

Stuart Heath

Jill Hooper

Kester Keighley

Colin Martin

Edward Martin

Paula Martin

Nick Rule

Julie Satchell

Contributors to the first edition

Jonathan Adams, Barrie Andrian, Adrian Barak, Martin Dean, Robin Denson, Chris Dobbs, Sarah Draper, Ben Ferrari, Robert Finegold, Antony Firth, Ian Friel, Debby Fox, Alison Gale, Cathy Giangrande, David Gibbins, Damian Goodburn, Alexzandra Hildred, Richard Larn, Thijs Maarleveld, Ian Oxley, Mark Redknap, Nick Rule, Paul Simpson, Kit Watson.


Every effort has been made to trace copyright holders and to obtain their permission for the use of copyright material. The publisher apologises for any errors or omissions in the above list and would be grateful if notified of any corrections that should be incorporated in future reprints or editions of this book.


The NAS Handbook – Why It Was Written

The original Archaeology Underwater: The NAS Guide to Principles and Practice was first published in 1992. It was commissioned to help address a scarcity of information about ‘how to undertake archaeological work under water while maintaining acceptable standards’ (Dean et al., 1992:2).

As well as explaining fundamental archaeological principles, this book provides a general introduction to archaeology under water, detailing techniques and practices as they are applied in an underwater context. It provides the tools appropriate to tackle a variety of sites in different environments and emphasizes that archaeology is not just a set of techniques - it is shaped by fundamental principles and theoretical parameters. While this book is a comprehensive source of practical information, it is not a complete reference book and will not transform the reader into an underwater archaeologist. Its aim is to provide an awareness of the responsibilities that go with any form of fieldwork while outlining what is involved in achieving an acceptable standard of archaeological work in what can often be a challenging physical environment.

In the intervening years since the publication of the first edition, while the basic principles have remained the same, technological developments have resulted in new and improved archaeological techniques. Meanwhile, the World Wide Web and satellite television have helped take underwater archaeology into peoples’ homes, feeding what appears to be an insatiable public appetite for all things associated with the past. In addition, links between countries with different approaches to archaeological investigation have strengthened and, as a result, the toolbox of techniques for archaeological work under water has grown.

In the light of such developments, an update to the text and graphics of the original book seems timely. The result is this long-awaited second edition of what is popularly referred to as ‘The NAS Handbook’.

The body that eventually became the Nautical Archaeology Society (NAS) was originally incorporated and registered as a charity in 1972 under the name (The) Nautical Archaeology Trust Limited. The Trust was reconstituted in 1986 as the Nautical Archaeology Society, mainly to oversee the production of the International Journal of Nautical Archaeology (IJNA), the first volume of which had been published in 1971, and more generally to further research. The Society is committed to the research, conservation and preservation of maritime cultural heritage. The NAS is based in the United Kingdom but has a significant international profile. Membership is made up of a wide range of people who wish to promote and be involved in the preservation of their coastal and underwater heritage, in its broadest sense.

This second edition of Underwater Archaeology includes several new chapters covering such topics as photography, legislation and conservation. Additional chapters reflect significant developments or new approaches, particularly with respect to project planning, safety on archaeological sites, historical research, monitoring and maintenance and geophysics.

Each individual component of this book was written by someone who is an expert in his/her field. The production of this second edition has been a long iterative process involving many people, most of them members of the Nautical Archaeology Society. Text from the original book has been modified, supplemented and, where appropriate, replaced. This book therefore owes its existence to everybody involved in the production of this and all previous versions (please see the list of contributors in the acknowledgements). The Nautical Archaeology Society would like to acknowledge all contributors with grateful thanks.

The Nautical Archaeology Society would also like to introduce the reader to the real underwater treasure - a rich cultural heritage that has helped shape the world in which we live today. By outlining the principles and practices of maritime archaeology, this book will enable people to make informed and responsible decisions about how to get the most from their involvement with maritime archaeology above or under water.