A subsea data collection and communication system is installed at a subsea interconnect point or subsea connector used for communication between subsea electrical, optical or hybrid electro-optical cables. The data collection and communication system is configured to collect system performance data such as voltage, current, optical pressure and the like from signals carried by the wires or fibers in cables connected to the connector unit, and may also collect data on environmental conditions from sensors installed in or on the connector unit, such as temperature, pressure, or sea water salinity sensors, and the like. The collected data is transmitted to a remote monitoring station or local hub for further processing to detect potential faults or performance degradation either at periodic intervals or on demand, using bi-directional Ethernet, CANBUS, a carrier frequency system over the cable power lines, optical signal over optical fiber, or wireless communication links over short distances.