Ensuring a high level of vessel traffic surveillance and maritime safety is determined by exploiting innovative ICT technologies and international cooperation among maritime authorities. Therefore, initiatives for maritime surveillance, global and regional integrations are realised through a collaborative, cost-effective and interoperable Common Information Sharing Environment (CISE). Consisting of the institutional network of maritime authorities that cooperate on various domains like safety, border control, environmental and rescue missions at sea, CISE enables the efficient transfer and economic exchange of maritime data and information via different interoperable systems using modern digital technologies. The ever-increasing amount of data received from heterogeneous data sources requires specific processing through the adoption of a Big Data framework which hosts, manages and distributes data to maritime users, contributing with great overall benefits to the CISE network core functionality. Specifically, this paper analyses the advantages of the Data Lake infrastructure, including its processes, techniques, tools and applications used to enhance maritime surveillance and safety across the CISE network. This part contains the deployment and interoperability achieved through the components of the participating command and control (C2) systems. Last, as a case study, an overview of the EU project EFFECTOR is provided which aims to demonstrate an end-to-end interoperability framework of data-driven solutions for maritime situational awareness at strategic and tactical operations.