By: Efrain Cruz
Each year in the United States, we remove 400 million cubic yards of sediment from channels and harbors--the equivalent of a four- lane highway, 20 feet (6 m) deep from New York to Los Angeles. New York's harbor is naturally 18 feet deep, but most ships need at least 45 feet to clear. Many European super ships require a draft of 65 feet. Ship size continues to increase, so dredging is a continuing and growing necessity.