2003 Diving Season - Page 1 of 3

 

The Diving Begins

 

Twenty one years after the hull of the Mary Rose was brought to the surface, archaeologists are again diving on the wreck-site. Their goal is to recover objects left buried within the seabed outside the hull, together with any remains of the hardware left over from the original excavation.

The seabed has changed in the 21 years. Over 50cms of sediment has accumulated over the site. All of this has to be removed to find the evidence left over from the excavation of 1979-1982.

To clear the sediment, divers are using an underwater vehicle on wide rubber treads with a suction pipe attached to it. This can be operated from the surface and is used to remove the upper layers. This is similar to using a JCB on a land excavation.

The objects within this layer are mixed, which suggests that the seabed is being disturbed nearby and is being redistributed over an area which includes the site. The modern seabed is made up of slipper limpets and other shells, like oyster shells, flints and coal within a very fine silt. This layer contains a mixture of artefacts including nineteenth century porcelain and a domino which is probably from the time of HMS Victory. Because this is a mobile layer, we cannot date the objects more exactly. Some items have been found which relate to the excavation of 1979-82, including an on/off tap for one of our airlifts (still numbered ‘port 7') and a white coffee mug.

 

Artefacts and any significant features have their positions fixed by placing an acoustic pole on top of them. This sends signals to four acoustic transponders which have been placed in the seabed around the site. These send signals to each other, and the distance is computed from the time it takes to send and receive the signal. The position of each of these has been fixed in the world using the global positioning system available through satellites. This system is also used to track the vehicle and divers.

All diving is undertaken using air supplied to the diver down an umbilical from the surface. The umbilical also has a communications and camera cable. This allows the diver to talk to the surface, and people on the surface to see and record what the diver sees. The divers descend to the wreck site using a wet bell, which operates just like a lift, but also has its own onboard emergency air supply, communications, cameras and lights.

Visibility is good, about two - three metres. It is however difficult trying to recognise shapes beneath the covering silt. The side of the hull hole is still a slope, but the middle is full of a dark and menacing ooze made up of liquid mud and seaweed to a depth of over a metre.

 

 

Back to top