Marine markers are navigational aids used in waterways to guide boats and ships. They come in various forms, including buoys, beacons, and lighthouses, and are designed to indicate safe passages, warn of hazards, or mark specific locations. These markers are often color-coded and numbered to help mariners identify their position and navigate effectively. The U.S. Coast Guard and other maritime organizations are responsible for maintaining these markers to ensure safe navigation. Each marker has specific meanings based on its color, shape, and light characteristics, helping sailors understand the surrounding environment and make informed decisions while at sea.