TRIDENT is the official acronym used for a funded European project entitled: "Marine Robots and Dexterous Manipulation for Enabling Autonomous Underwater Multipurpose Intervention Missions". This project has demonstrated a new approach for multipurpose underwater intervention tasks with diverse potential applications ranging from underwater archaeology and oceanography to the offshore industries. The methods and technologies defined and tested under TRIDENT go beyond present-day methods typically based on manned or purpose-built systems. The project was launched on 1st of March 2010 and has been running for a total of 36 months, achieving the "excellent" grade in its final review process by the European Commission ( May 2013, UJI, Spain). In this paper the last achievements will be discussed, highlighting the main research efforts continuously supported by the consortium till reach its final objectives. In summary, TRIDENT represents a new benchmark for the scientific community, solving the underwater "search & recovery" problem, in shallow water conditions, with the highest level of autonomy ever seen before.