Page 40 - Green - Maritime Archaeology: A Technical Handbook. 2nd ed

Chapter 2: Research 19
with regard to access roads and topographical features. Generally, Admiralty Charts are less up-to-date than land maps. The latter tend to be kept updated at regular intervals as the features on land change more rapidly with building works, etc.
The Admiralty Charts give details about the type and nature of the seabed, currents, depths, etc. The Pilots should also be consulted. These are published by the Hydrographic Office in the UK and give details of wind, weather, and local information about the area. In particular, everyone should have access to a copy of the Catalogue of Admiralty Charts and other Publications (Hydrographer of the Navy, 1980) which lists all the charts of the world and is very reasonably priced.
The next line of approach is to locate aerial photographs of the region. In a number of countries aerial photographs are available at low cost from lands and survey departments. It is worth getting the best possible cover- age and, in particular, stereo pairs are useful because they can be utilized to produce maps of the area, if none are available. It is worth getting a copy of the ground control data as well, as these can be used to identify trig sta- tions and survey points.
Clearly, the person going into the field should be equipped with as much of the available information about the site and the area as possible. It is advisable to have, or to produce, a large-scale working map for survey purposes.
IV. PREPARATION
Preparing to go into the field can be a difficult exercise. It is necessary to have a clear idea of what is to be done and how it is to be executed. Make a list of objectives; this is often called the research design and can be a survey or excavation or some plan of what you intend to do. The plan will depend on a number of other factors like budget, staffing, equipment, loca- tion, etc. The aim will, to a large extent, be to determine a lot of the other factors.
For example, how would one go about a limited, exploratory excavation of a remote, but known site—that is the aim. Let us examine a real site, by way of illustration, the Trial wreck site, some 15 nautical miles off the Monte Bello Islands in the northwest of Western Australia. This site was investi- gated briefly in 1971 (Green, 1977a). In 1985 a further survey was under- taken in order to try to conclusively identify the site (Green, 1986b). The site lies in shallow water on the southwest corner of Trial Rocks, but is exposed to strong currents and heavy swells. The nearest land is the unin- habited Monte Bello Islands which are about 80 nautical miles from the nearest mainland port. Obviously, a base camp on the Monte Bello Islands