LIST OFFIGURES ix
11.10 Temporary transits formed by setting up
paired ranging rods along a shore baseline 91
11.11 Surveying a submerged site in shallow water
using a shore-based EDM 92
11.12 Differential GPS system with satellites,
shore-based reference stations and
in-boat mobile receiver 94
12.1 Towed diver search 97
12.2 Swimline (freeline) search 98
12.3 The offset method in use (with
metal detector) 99
12.4 Jackstay (corridor) search 100
12.5 Circular search 101
13.1 500 kHz sidescan sonar image of a
v-shaped fish-trap from the River
Barrow, County Wexford, Ireland 107
13.2 Sidescan sonar image of the
SS Storaa(1943) 108
13.3 Chirp and Boomer image from
Strangford Lough, Northern Ireland 109
13.4 A two-dimensional profile and interpolated
timeslice of the Grace Dieu(1439) wreck,
River Hamble, Hampshire, UK 110
13.5 Geophysics equipment: 1) magnetometer,
2) sidescan sonar, 3) sub-bottom
profiler, 4) ROV 112
14.1 Excavation plan of part of the Spanish
Armada wreck La Trinidad
Valencera(1588) 115
14.2 Representing the sea-bed using symbols 116
14.3 Radial method of survey 117
14.4 Recording the profile of a wreck using
vertical offsets from a horizontal datum 120
14.5 Offset method, including plotting results 121
14.6 Ties/trilateration: survey and drawing
up results 122
14.7 The principle of levelling to establish
relative heights/depths 124
14.8 Depth relative to a temporary benchmark 124
14.9 A simple clinometer 125
14.10 A double-strung planning frame 125
14.11 A diver taking DSM measurements 128
14.12 Braced quadrilateral (3-D survey) 129
14.13 Joining quads (3-D survey) 129
14.14 Measuring between quads (3-D survey) 129
14.15 Good control-point network shapes
(3-D survey) 130
14.16 Secondary points (3-D survey) 130
14.17 Poor control-point network shapes
(3-D survey) 131
14.18 Positioning detail points on features using
control points (3-D survey) 132
14.19 Surveying a submerged site in shallow
water using a shore-based ‘total station’ 13315.1 Excavation strategies: trench and test pits 136
15.2 Probing to record sediment depths and
obstructions 136
15.3 Use of air or water probes 136
15.4 Optimum place for tree-ring sampling 138
15.5 Taking a spot sample 139
15.6 Column or monolith sampling from a
section 140
15.7 Excavating a wooden weaving heddle
on the Armada wreck La Trinidad
Valencera(1588) 142
15.8 Excavation tools: the trowel and the
paint brush 142
15.9 A conservator removing the surviving
section of a gunpowder barrel, excavated
from the Spanish Armada wreck La
Trinidad Valencera (1588) 143
15.10 Excavation using airlift 144
15.11 Water-dredge operation 146
16.1 Teredo navalis(shipworm) 150
16.2 A concretion recovered from the Duart
Point wreck (1653) site, Mull, Scotland 152
16.3 An X-ray of the concretion shown in
figure 16.2 152
16.4 The Duart Point sword hilt shown in
figures 16.2 and 16.3 after conservation 152
16.5 Excavating a small fragile object – a leather
water-bottle – from the Armada wreck
La Trinidad Valencera (1588) 155
16.6 Raising a large organic object – a spoked
wooden wheel – from the Armada wreck
La Trinidad Valencera(1588) 155
16.7 The leather water-bottle shown in
figure 16.5 is brought to the surface
and handed to the waiting conservator 155
16.8 A pocket sundial with integrated
compass found on the wreck of
the Kennemerland (1664) 161
17.1 A covering of sandbags placed over
a fragile area on the Duart Point
(1653) wreck, Mull, Scotland 168
18.1 Archaeological illustration in practice 171
18.2 Recording shape: tracing round an
object with a set-square and pencil 173
18.3 Recording shape by establishing a vertical
datum and taking offset measurements 174
18.4 A radius template in use 174
18.5 A radius chart in use 174
18.6 Correct orientation of a pottery sherd
when using a radius chart 175
18.7 A simple pottery drawing 175
18.8 Thickness-gauge callipers in use 176
18.9 Archaeological illustration of a jug
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