Types of Survey

Surveys on archaeological sites can broadly be divided into

four types:

1 assessment survey;

2 recording survey (including pre-disturbance and

excavation surveys);

3 monitoring survey;

4 topographical survey.

The end product for each survey type is the same – the

site is recorded to a known level of detail and accuracy.

An assessment survey provides information on which

a fieldwork strategy can be based. It can be used to

find the extent of the site before embarking on a more

detailed pre-disturbance survey (see below). It can also

provide information on the range, type and stability of

archaeological material surviving on the site. This is

important because such information can affect decisions

about what action should be taken and when. Such a

survey could help decide the location of primary survey

I

t has been shown elsewhere in this book that fieldwork

should be undertaken with clear aims and objectives

that are defined in the project design. It may be that

the survey alone answers the questions posed by the

project design, so an accurate site-plan can be the end

product of the fieldwork rather than just one phase of

a project.

The aim of this section is to give an introduction to basic

survey techniques used in underwater archaeology. The

techniques described here are the same as those used in

archaeology on land, as well as in civil engineering and

building work. Surveying is not the same as searching;

divers looking for wreck remains are searching, while

divers recording the positions of those remains are sur-

veying. The purpose of a survey is to produce an accu-

rate picture of the site, usually as a two-dimensional plan

(figure 14.1) with supporting descriptions and measure-

ments. In essence, this is an attempt to re-create, on

paper or in a computer, the site as it exists now, and before

it is disturbed. The site-plan must be an accurate repre-

sentation, so it is not acceptable to simply sketch or guess

where things are.

Contents

u Types of survey

u An initial sketch

u Planning

u Setting up a baseline/control points

u Installing survey points

u The principles of survey

u Survey using tape-measures, grids and

drafting film

u Vertical control (height/depth)

u Drawing/planning frames

u Grid-frames

u Processing measurements and drawing

up the site-plan

u Three-dimensional computer-based

survey

u Acoustic positioning systems

u Positioning the site in the real world

Underwater Survey

14

Underwater Archaeology: The NAS Guide to Principles and Practice Second Edition Edited by Amanda Bowens

© 2009 Nautical Archaeological Society ISBN: 978-1-405-17592-0