Divide the class into teams. Give each team a photograph of an ocean floor or desert scene and a piece of graph paper. Ask them to imagine they are archaeologists who are looking for treasure under the sand or sea. Have them decide what the treasure is and how it ended up there. Then have them plot a map of exactly where they think the treasure might be located. Be sure to draw any landmarks that will serve as reference points. Ask one student from each group to explain their graph and what they hope to find.

Ask these questions: How is the work of marine archaeologists different from the work of dry land archaeologists? How do you think marine archaeologists preserve the integrity of a site and its contents during and after the initial discovery?
 

The Henrietta Marie's trip began in 1700 in London. The ship stopped in Africa to trade glass beads, guns, and pewter to tribal chiefs in exchange for a human cargo of 190 African slaves and continued on to Jamaica and sold the slaves to plantation owners, but never returned to London from there. It was overtaken by a violent storm and went down off the Florida coast.

We know the details of the Henrietta Marie's voyage as a direct result of a painstaking sleuthing of marine archaeologists and historians. Marine archaeologists unearthed the ship's artifacts in 1982. Using items such as the bell and shackles, historians pieced together the ship's saga, providing a rare look at how slave ships operated.

The first step for archaeologists was to establish a base line and grid on the ocean floor around the wreck to serve as reference points. Then they began mapping out where artifacts were discovered.

Some of the 7,500 artifacts were covered with layers of encrustation made up of the tiny skeletons of microorganisms. As one group of the organisms died, another would attach itself on top of the original layer. Other ship artifacts were preserved by layers of sand, creating an absence of oxygen that protected them from microorganisms that feed off organic matter, waves, and other forces of nature. Conditions such as the depth at which the wreck was found and the cold temperature of the ocean also helped to preserve the artifacts. 

After carefully gridding, tagging, and excavating artifacts from the site, conservationists removed sand and small shell encrustations. Then, in a lab, they removed any rust from metal artifacts through a process of electrolytic reduction, where the oxidation (or rust) process is reversed. Some artifacts are beyond help for this method to work, but if the layers of encrustation are thick enough, they can be filled like a mold with an epoxy resin to create casts or replicas of the pieces.

 What is finally preserved provides us with a time capsule, a glimpse into the past, particularly the conditions of the slave trade during that period. This glimpse may help us to understand our history and move more wisely into the future. 
 

1. Archaeological discoveries like the Henrietta Marie change the way we view history. How do they affect our view of the present and future? 

2. How do recent discoveries like those made by astronomers about the surface of Mars or by biologists working in Antarctica and the Amazon rain forest change our understanding of life on Earth?
 
 

 Work in teams to create the story and site of a shipwreck in a tub or aquarium filled with sand and water. Explore another team's site to grid, tag, and excavate the artifacts. Record information about each item as you excavate and analyze it, then present your findings to the other teams of marine archaeologists.
 
 

Materials
 
 

1. Work in teams to create a story of a shipwreck: What kind of ship was it? What was it carrying at the time it sank? How and when did it happen?

 2. Gather a variety of objects that represent what might have been on the ship. Make a detailed list of your artifacts, including size, shape, and material.

 3. Cover each one with clay to represent the encrustations on artifacts encountered by marine archaeologists.

 4. Cover the bottom of your container with a layer of sand. Fill with water.

 5. Arrange your artifacts in and under the sand.

 6. Move to another team's site to explore and excavate their artifacts. (That team should keep the story it wrote secret for now-the new team examines only the artifacts.)

 7. Use string tied to toothpicks to set up a grid in the sand around the site or main artifacts. Record the grid on graph paper, and then record the location where each artifact is discovered.

 8. Use a data log to record a description of each item as you find it. Think about what information is important to include.

 9. Use plastic utensils and water to carefully remove any encrustation found on the artifact. Record your findings.

 10. Observe your artifacts and analyze your data log. Write a story that might be consistent with the artifacts you found. Present your findings and interpretations to the other teams of marine archaeologists. How closely does your story compare to the one devised by the team that created the site?

Questions

 1. How does the process of discovery by excavation compare to the investigative process used by other scientists?

 2. What "experts" could help marine archaeologists determine the nature and historical context of their discoveries?

 3. How might a metal detector aid in the investigative process?