Today's Technology As we have become more technologically advanced, we have lessened some of the risks of being at sea, and improved the chances for survival at sea, but the dangers are still there. Activity 2 Let's look at some of the advances in technology that have made it safer to sail the seas. As you read the next pages, match each advancement in technology that is listed on your Worksheet with its description. Also, watch for links to web sites that you can use to see pictures of those items. Most of the world's coastlines have been mapped on detailed nautical charts allowing ships' crews to know the depth of the water and any submerged dangers and reefs. Let's look at a chart. Did you see all of the numbers on the chart? Those numbers indicate how deep the water is in each of those spots (in feet). Many dangers in the water, such as shallow water, submerged objects, narrow channels, and reefs have been marked by buoys, lighthouses, and other markers. These markers are also indicated on the detailed charts. Using these symbols, go to the chart and see if you can locate a buoy and a lighthouse. There are several on the chart. The U.S. Coast Guard maintains these objects so sailors will be aware of the dangers. A global positioning system (GPS) now allows ships to pinpoint their exact positions on the charts using satellites. Depth sounders allow ships to know how much clearance is between the ship's hull and the seabed. All of these combined have reduced the risk of ships going aground. Did you find answers for charts, buoys, lighthouses, GPS, and depth sounders on this page? If not, go back and look again. If you found all of them, continue looking at technological advances (and more answers) on the next page.