Underwater construction works in port areas have mostly depended on divers. It is necessary to develop a new type of mechanized underwater equipment for economical, effective and safe utilization for port construction, which complements a traditional method using divers, especially for underwater leveling works of rubble mound. A project in Korea recently commenced to develop and make practicable unmanned underwater excavation equipment, monitoring system for the underwater environment, and underwater management system. In this study, the specification of the equipment and attached apparatus was determined, and conceptual design of the underwater excavation equipment with underwater monitoring system, underwater management system was performed. An onshore type of remotely controlled system was fabricated and the performance of the equipment was verified in a field condition. The results of this research can be expected to increase the effectiveness of underwater works and to practically utilize to the real fields after performing various field tests with the developed equipment.