Day beacon

A day beacon (sometimes daybeacon) is an unlighted nautical sea mark. A daymark is a signboard attached to it that presents navigational information in a standard shape (square, triangle, rectangle, rhombus) and color. Day beacons typically mark channels whose key points are marked by lighted buoys. They may also mark smaller navigable routes in their entirety. They are the most common navigation aid in shallow water, as they are relatively inexpensive to install and maintain. Navigation around them is similar to that around other navigation aids.