| Scientists know more about the surface of the moon than they know about the ocean floor. Ocean water covers 71 percent of the Earth's surface. Yet, more than two-thirds of the land beneath it remains unexplored. In fact, only five percent of the ocean floor has even been mapped.
Not too far from Maine, the change in tides can be four stories high. The Bay of Fundy lies off the coast of eastern Canada between the provinces of New Brunswick and Nova Scotia. There, the difference between high and low tide can be as much as 43½ feet (13.25 m). Twice every day, billions of tons of seawater roll in and out of the bay — an amount that's about the same as the daily flow of all the freshwater rivers in the world.
From its name, you can tell what kind of craft any U.S. Navy ship is. During World War II, the United States Navy began naming ships with a system that is still used today. Battleships are named after states. Destroyers are named in honor of dead persons associated with the Navy or Marines. Submarines are named after fish and other sea life. Hospital ships have words synonymous with kindness in their names. And storage ships are named after astronomical bodies.
It's easier to do the dead man's float in the Dead Sea than in the ocean. The higher the salt content in water, the more dense and buoyant it is. Although oceans are filled with saltwater, they're not the saltiest bodies of water on Earth. Both the Dead Sea, in Israel, and the Great Salt Lake, in Utah, are saltier.