National Museum of the U.S. Navy

Background

Navigation, in its simplest form, means to find your way to a point and back again. For sailors, navigation means guiding a ship through water without the help of road signs. Early sailors navigated in inland rivers and waterways which was simple. When sailors ventured out into the sea, they remained close to the coastline, using towns and the shoreline to mark their journey. A sailor's feel for the sea, the directional guidance of the sun, landmarks, and oral directions framed the earliest navigational aids.

Later, sailors looked to the heavens for a more reliable means of navigation. The development of the compass and the quadrant allowed sailors to move with some certainty on the sea. Using the North Star as a landmark, sailors sighted the star with a quadrant, measured the angle from the horizon and identified the latitude. Once the ship reached the correct latitude, it sailed east or west to reach its destination. Sailors could tell how far they were going in either direction by locating the lines of longitude. Nautical direction was determined by the magnetic needle of a compass. In the days of sail, courses and bearings were given in points around a compass.

Soon, sailors began to draw charts and record their paths and directions. In 1842 Matthew Fontaine Maury, a United States Naval officer, instituted a series of Wind and Current Charts and Sailing Directs. These charts and publications established ship lanes and revolutionized navigation on the seas. In the 20th century navigation became more reliable and sophisticated. During World War II, sailors used different types of radio wave navigation to help planes and ships find their locations, as well as find enemy ships. Today, sailors on most large ships use satellite and computer technology, such as GPS (Global Positioning Satellietes), to guide them on the seas.

Activities

• Biography: Matthew Fontaine Maury
• Research and Report
• Vocabulary
• Word Search
• Charting the Seas: Latitude and Longitude Activities
• Other Navigation Activities
• Answer Key

Research and Report

1. Research the following forms of navigation below and explain when and how sailors used each. What were the positive and negative aspects of earlier navigation? What are the positive and negative aspects to modern forms of navigation?

Dead Reckoning

Electronic Navigation

Celestial Navigation

GPS

2. Name three navigational tools used before electronic navigation machines were developed. How did these earlier tools work?
   
   
3. Some sailors use stars to navigate. What were the most important stars to sailors and why? What devices did sailors use before electronic navigation was invented if they could not see the stars?
   
   
4. Why is it important to know the ocean's winds and currents when navigating?