An OceanCube® is a cabled coastal observatory system designed to collect continuous real-time data and under-water images for scientific research and long-term envi- ronmental monitoring. A central node supports a variety of biological, physical, and chemical sensors and is optionally connected to as many as four satellite nodes at the corners of a cubic volume that provide current and temperature information. To observe the behavior of fish, stereo camera modules with hydrophones can also be connected. A cable from a shore laboratory to the central node is used to supply power, remotely control individual instruments and to transfer data back to shore at high speed.