People use an alphanumeric grid map to quickly identify the location of something. For example, if they need to locate a specific area in the ocean, they can use the alphanumeric grid map to pinpoint the coordinates of that area. The alphanumeric grid map divides the area into a grid system, with each section assigned a specific alphanumeric code. By referencing the grid coordinates, people can navigate and track the ocean currents, locate research stations, and even determine where animals are located. It provides an efficient and precise way to communicate and identify locations, saving time and ensuring accurate information.