This paper provides an overview of the CLAM project, which aims at developing a collaborative embedded monitoring and control platform for submarine surveillance by combining cutting edge acoustic vector sensor technology and 1D, 2D, 3D sensor arrays, underwater wireless sensor networks protocol design, advanced techniques for acoustic communica- tion, new solutions for collaborative situation-aware reasoning and distributed data and signal processing and control for horizontal and vertical sensor arrays. The result will be a new system architecture accommodating pervasively distributed heterogeneous sensor nodes deployed at different water depths, which provides a flexible, reconfigurable, and robust platform for online surveillance of submarine environments. Horizontal and vertical collaboration between sensor arrays by means of beam forming, sensor fusion and distributed processing and reasoning enables fine-grained monitoring of the submarine environment and collaborative event detection as well as transmission of the network information to the monitoring stations such as buoys and AUVs.