New at the Archive: Fishfinders

During the Second World War the Navy developed a new technology to find enemy submarines underwater. This was called ‘ASDIC’, and was based on the understanding that sound signals could be transmitted into the water and any echo would be heard if the sound wave hit a solid enough target. The echo could be detected by a hydrophone and displayed on a suitable display screen, showing distance from sound source to sound echo and also the direction that the sound source was sent away. Continue reading “New at the Archive: Fishfinders”