The Coastal Acoustic Buoy (CAB) uses passive acoustics to monitor marine mammals and measure underwater noise via a cost effective and easy to deploy platform. CAB is a versatile platform ideal for a variety of applications including Marine Mammal Mitigation, Underwater Noise Monitoring, and Scientific Research. Lightweight and cost effective, CAB is easy to deploy and can detect all species of vocalizing marine mammals with the ability to sample up to 500 kHz.