Underwater Smart Communication Buoy for underwater passive surveillance in open sea upto depth of 200m with feature to surface at regular intervals for transmission of data to base station through satellite communication. The buoy should have the capability to operate autonomously at variable programmed depth & Location, collect acoustic data, and employ edge computing for data analysis and transmission of only critical data to base station via satellite link. The buoy should be compact, smart and self sustaining upto 90 days in open seas without human intervention