Later, in 1980 when Terram, an inert blanket of geo-textile, became avail-
able we used it to clad all the exposed timbers. Any pockets in the blanket
provided homes for squat lobsters and damage to the blanket allowed irriga-
tion and inevitably more Limnoriainfestation. The problem was to secure the
textile closely to a three-dimensional structure. The ship was open as a
wreck. Ribs, planking, deck beams and knees were exposed in situ. There
were no flat surfaces. It took dedication and hard work to wrap the exposed
surfaces with the Terram. To secure the blanket over the winter 1980/1981 we
filled the excavation with a washed gravel aggregate. This was supposed to
be 50 mm in diameter, but many were 100 mm. It was time-consuming to
remove, but unmistakable, and it reflected the light well, an important point
when underwater visibility was often reduced to 1 m.
In other parts of the world, a synthetic grass mat has been used to collect
current-borne sediments enabling a protective mat of sand to accumulate. In
Boa Vista, Cape Verde Islands the natural seabed is composed of water-worn
pebbles of volcanic rock. These are easy to handle underwater and a layer of
100 mm pebbles overlain with some well-chosen boulders protects the site
from marine and human interference. The insertion of a short tail of orange
cord serves as buried marker. It is discrete, moving gently in the current, and
to the casual intruder is much like other marine growth and debris.
What one cannot do is walk away from an underwater site and rely on your
favourite deity to preserve it. By your intrusion into the environment of the
wreck you will have jeopardised its chance of survival. The Guernsey wreck
was nearly destroyed by being exposed by the propeller thrust of legitimate
shipping using the harbour. In two or three years it would have been
destroyed. Thankfully the amateur diving archaeologist who found the site
received the support of his local club who were prepared to do anything asked
of them. He also had the acumen to contact professional archaeologists, sci-
entists and conservators who managed the project. This cooperation and
respect within a multidiscipline team is essential.
The need for on-site conservators and recorders is obvious. Some details
like paint marks on wood or stone are often fugitive and light labile, as were
the markings on the parts of a seaman’s chest from the Mary Roseindicating
how they fitted together. Obviously it was a flat-pack kit purchased for later
assembly. Within 20 minutes the marks had been photographed, but they
were beginning to fade and there is no trace of them today.
3 Conservation with a Purpose
The importance of conserving cultural material is obvious. The public expect
it, and the specialist also expects to be able to reassess the evidence. The
material should also, whenever possible, be available for study and exhibition
10 Chapter 1