Scuba divers examining a shipwreck underwater.
Virtual Fieldtrip
Come learn about archaeology, Maryland's history and some sites at the Park.

Excavation

excavation.jpgMost underwater sites are not excavated, but when they are, they present special obstacles.  Sediment, the soil that has settled on the bottom of the river or ocean,  needs to be removed systematically without damaging anything and without clouding the water, making it harder for divers to work.

Archaeologists use either an airlift or a water dredge to suck up the  sediment and bring it to the surface, like a large underwater vacuum cleaner.  The sediment needs to be screened, just like at a site on land, to find small artifacts that the divers missed.

Above, four divers use an airlift to remove sediment from a site. As they uncover parts of the site, they will make notes.  In fact, a written description of every day’s work is prepared by the site director, as well as by each person excavating.

Below, a team member monitors the end of the airlift, which drops the water and sediment into a screen located on the barge.   Artifacts will remain in the screen until they are bagged by provenience, or the artifact’s location within the site.  The sediment is then hauled off site by a barge.

Scorpion Project Picture Compilation 213.jpgarchaeology


At the end of the day, divers compare notes, an important step in controlling the accuracy of the information collected. Since it is hard for them to talk underwater and very easy for things to be misunderstood, they will double check everything when they come up.

 

 



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