1000 Things You Should Know About Oceans is a fantastic reference resource. Each of the 100 subjects are covered in ten key facts and accompanied by detailed artwork and photography. Explore life beneath the waves and find out some incredible facts like: oceans cover almost 362 million sq km of the earth's surface. The first modern fish appeared around 250 million years ago. The size of a seahorse ranges from less than one centimeter to 13cm.