The present invention includes systems and methods for a continuous-wave (CW) radar system for detecting, geolocating, identifying, discriminating between, and mapping ferrous and non-ferrous metals in brackish and saltwater environments. The CW radar system generates multiple extremely low frequency (ELF) electromagnetic waves simultaneously and uses said waves to detect, locate, and classify objects of interest. These objects include all types of ferrous and non-ferrous metals, as well as changing material boundary layers (e.g., soil to water, sand to mud, rock to organic materials, water to air, etc.). The CW radar system is operable to detect objects of interest in near real-time.