Coastal waters are those parts of the ocean closest to the land. They start where the breakers hit the beach and then stretch seaward as far as 100 nautical miles (approximately 115 miles or 185 km). Any bays, inlets, coves, harbors or sounds in this range are also considered part of the coastal waters. In some cases, coastal waters are thought to extend as far as the continental shelf. Coastal waters play a unique ecological role for oceans. Countless fish and other marine species use these areas during at least part of their life-cycle, maybe to reproduce, maybe to feed, or maybe as a way to migrate from one place to another. Coastal waters are also important to people as this is where we obtain most of our food and energy (like oil, wind and wave energy); and where most of our sea-going traffic is concentrated. To begin exploring, click on one of the ecosystems listed below.