Fish finding devices are tools used by anglers to locate fish underwater. These devices use sonar technology to send sound waves into the water, which bounce off objects like fish and structures. The information is then displayed on a screen, showing the depth and location of fish, making it easier for fishermen to target their catch. There are various types of fish finding devices, including handheld models and larger units mounted on boats. Some advanced devices also offer features like GPS mapping and underwater cameras, enhancing the fishing experience by providing detailed information about the underwater environment and fish behavior.