depth sounder

A depth sounder is a device used to measure the depth of water beneath a boat or ship. It works by sending out sound waves (sonar) into the water, which then bounce off the bottom and return to the device. The sounder calculates the distance based on the time it takes for the echoes to return. This information helps navigators avoid underwater hazards, determine fishing depths, or map the seafloor. It provides real-time, accurate depth readings, enhancing safety and situational awareness during maritime activities.