a lunar month. The golden rule is that preservation, i.e.protection, begins
at the moment of discovery and not when the object is sent ashore to the
laboratory.
In Guernsey, Channel Islands, the remains of a 3rd century merchant ship
lying in shallow water (4.8 m below chart datum) were covered with 16 tons
of sandbags to protect the timbers. They were swept away in one storm leav-
ing the site dangerously exposed (Rule and Monaghan, 1993). Thankfully,
volunteer divers braved the winter weather to replace them, building the
mound carefully like a Flemish bond brick wall. Their care saved the timbers
and they are now awaiting display in St Peter Port.
Loose timbers that were swept away from this wreck soon after exposure
in 1984 were attacked by gribble and in 12 months all surface detail was lost.
After 24 months exposed loose timbers had lost 50% of their bulk and were
virtually unrecognisable (see Figure 4).
In the early days of the Mary Rosevolunteers did the work. They were
dedicated divers who had searched for the wreck and who limited excavation
to minimum disturbance. The ship and her contents had been preserved in
mud, sand and silts that provided an anaerobic environment and inhibited
micro- and macro-biological degradation. One of the major problems was
caused by infestation with Limnoriasp. To prevent or limit this infestation we
backfilled the area with the mud removed during the excavation. This was
only moderately successful. The upper levels of mud in this area of the Solent
are not clean and it was rather like throwing a dirty cocktail of mud and efflu-
ent over the cleaned and newly exposed timbers. After many discussions with
scientists at the University of Portsmouth and Imperial College, London we
chose to blanket the area with hessian covered with sandbags. 1000-gauge
Polythene, the first choice, proved to be too difficult to handle underwater.
Introduction 9
Figure 4Detached timbers eroded by teredo in the upper levels of sediment below the stern
castle (Mary Rose)