Remote sensing is just what it sounds like – detecting things from a distance.  In this case, archaeologists use a variety of devices to look at sites in different ways. Each device gives the archaeologists a separate kind of information, which is then analyzed and interpreted. Some of the most commonly-used devices are magnetometer, sidescan sonar, and hydroprobe. Sometimes ROVs – Remote Operated Vehicles – basically underwater robots – are used to survey and film the site.

But even with all this technology, the archaeologists need to see the site themselves and will do what is called a dive inspection.  They dive in and examine the site firsthand.

Once the location is decided, a dive team and support team are gathered together.   A surface platform is positioned over the site and this is where all the supplies and team members stay. Depending on the site, this could only be one or two small boats, or on a large project, it could be many boats and barges connected together, like you see below.

Divers can only stay underwater for a limited time, and must take breaks between dives, so work is often very slow, even with many divers.   On the right, two divers prepare to enter the Scorpion dive site- notice their wet suits to  protect them against the cool temperatures of the Patuxent River water.  They also have special facemasks that allow them to communicate with the team on the surface.  A rope line is also attached to the divers as a backup in case the communication system fails.

A large support team stays on the surface in boats or barges in order to monitor the divers and receive material from them.  Above left, one team member is monitoring communications with divers using a headset.  Behind him are the extra oxygen tanks needed.

To the left is an example of a barge set up to explore the suspected Scorpion site in Maryland, with various crew members preparing a diver to enter the site. You can see that the dive site is very close to the river’s edge; in fact the water here is only about 6 feet deep!