When you think of ships, whether you’re thinking of the Titanic, pirate ships, or trading vessels crossing the vast ocean to bring goods and services from one country to another, you probably picture them with an anchor—a heavy metal hook designed to catch on the ocean floor and keep a boat or ship in place. Wikipedia says this about anchors: There are two main types of anchors: temporary and permanent. A permanent anchor is called a mooring block and is not easily moved. A temporar...