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Lost at Sea—The Search for Longitude

Classroom Activity

To research and chart the shortest course to circumnavigate the globe.

Materials for each team
  • copy of "Voyage Around the World" student handout (HTML)
  • world map, globe or atlas, with a scale
  • small tacks, pins or self-stick notes (for marking locations)
  • a 12-inch piece of string (for measuring distances)
  1. Organize students into groups and distribute student handouts and materials to each group. Explain that the challenge is to research and chart a course that takes them to each Checkpoint Destination on their way around the world once. Have students review the Nautical Rules and Checkpoint Destinations before beginning. (You may delete or change Checkpoint Destinations to best suit your students' abilities.)

  2. Have students research locations that match the Checkpoint descriptions, plot these locations on a map, record the latitude and longitude for each, and plan their course from one location to the next. Then have them estimate the distance between locations, using the string and a map scale.

  3. When teams have completed their routes, have them exchange maps and recording charts to compare Checkpoint locations and estimated distances. Then, as a class, come up with the shortest route possible.

  4. As an extension, you can have students convert the estimated distances from statute miles to nautical miles.

Activity Answer

Because the Checkpoint Destinations are open-ended, the locations and courses students choose will vary (see sample course below). When students present their locations, courses and estimated distances, they should be able to explain why each location matches the Checkpoint description, how they chose the course, and the method they used for estimating distances. Most maps students will be using show statute miles, the unit of measurement for distances on land. Distances at sea are measured in nautical miles. A nautical mile is found by dividing the Earth into 360 degrees, and then dividing each degree into 60 minutes. One nautical mile equals one minute, or 1/21,600 of the Earth's circumference. Students can convert statute miles to nautical miles by dividing the number of statute miles by 1.1508.

Sample Course

Checkpoint Destination


Latitude and Longitude

Estimated Distance from Previous Checkpoint

1. Start in Greenwich, England

Greenwich, England

51° 29'N, 0°00'W

0 miles

2. Dodge an iceberg.

Reykjavik, Iceland

64° 09'N, 21°58'W

1,230 miles

3. Dock next to a cruise ship.

St. Thomas, U.S. Virgin Islands

18° 20'N, 64°55'W

4,010 miles

4. Stop at a Spanish-speaking port.

Panama Canal

9° 10'N, 79°37'W

1,540 miles

5. Stop at an English-speaking port.

Los Angeles, California

34° 00'N, 118°15'W

3,700 miles

6. View a high mountain from a port.

(Mt. Ranier) Seattle, Washington

47° 35'N, 122°20'W

1,540 miles

7. Visit a major oil-supplying port.

Valdez, Alaska

61° 07'N, 146°17'W

1,230 miles

8. Photograph a kangaroo.

Sydney, Australia

33° 55'S, 151°10'E

9,560 miles

9. Sight a penguin.

Balleny Islands, Antarctica

66° 30'S, 163°00'E

2,470 miles

10. Collect exotic spices.

Jakarta, Indonesia

6° 09'S, 106°49'E

4,320 miles

11. Have lunch in a country where rice is a dietary mainstay.


1° 17'S, 103°51'E

620 miles

12. Visit a country that has changed its name within the past 50 years.

Sri Lanka (Ceylon)

7° 30'S, 81°50'E

1,540 miles

13. End in Greenwich, England.

Greenwich, England

51° 29'N, 0°00'W

8,020 miles

Total Distance

(statute miles)

(nautical miles)

Links and Books


Hobden, Heather, and Mervyn Hobden. John Harrison and the Problem of Longitude. Lincoln, England: Cosmic Elk, 1989.
Includes a history of John Harrison and his invention of the maritime chronometer, which solved the problem of finding longitude at sea.

Sobel, Dava. Longitude: The True Story of a Lone Genius Who Solved the Greatest Scientific Problem of His Time. New York: Walker, 1995.
Takes the reader back to the maritime world of 1714, when finding the solution to the problem of determining longitude at sea was of the highest scientific, political and economic priority.

Web Sites

NOVA Online—Lost at Sea: The Search for Longitude
Will include an interactive game that provides a way to understand why knowing the time at your home port allows you to fix your longitude at sea. The site will also feature how the Global Positioning System works, a time line of ancient navigation, and contributions from leading experts on what they believe are some of the greatest scientific challenges of our day. Launch date: Currently available.


The "Voyage Around the World" activity aligns with the following National Science Education Standards and Curriculum and Evaluation Standards for School Mathematics:

Grades 5-8

Science as inquiry

Science Standard G:
History and Nature of Science

Science as a human endeavor

  • Science requires different abilities, depending on such factors as the field of study and type of inquiry. Science is very much a human endeavor, and the work of science relies on basic human qualities, such as reasoning, insight, energy, skill and creativity—as well as on scientific habits of mind, such as intellectual honesty, tolerance of ambiguity, skepticism and openness to new ideas.

Mathematics: Computation and Estimation

Mathematics Standard 7:
Computation and Estimation

Math: Measurement

Mathematics Standard 13:

Grades 9-12

Science as inquiry

Science Standard G:
History and Nature of Science

Science as a human endeavor

  • Individuals and teams have contributed and will continue to contribute to the scientific enterprise. Doing science or engineering can be as simple as an individual conducting field studies or as complex as hundreds of people working on a major scientific question or technological problem.

Teacher's Guide
Lost at Sea—The Search for Longitude

Video is not required for this activity