Ocean Networks Canada (ONC) is one of the world's largest and most advanced cabled ocean obervatory. It is composed of many obervatories, the largest one being the North East Pacific Time-series Underwater Networked Experiment (NEPTUNE) coastal network.

The NEPTUNE cabled ocean observatory, completed in 2009, is a versatile multidisciplinary subsea system. Its backbone infrastructure comprises 800 kilometer loop of telecommunication fibre-optic cables to power and transfer data to a variety of sensors. It has been designed for long-lived, highly reliable underwater operations. The high-speed data link and high power is available at 5 nodes across the Juan de Fuca tectonic plate (200,000 square kilometers) off the coast British Columbia. Each node acts as a hub for core observations and experiments. A total of 17 primary junction boxes are cabled to the nodes and used to connect hundreds of instruments including traditional oceanographic sensors, cameras, hydrophones and other complex systems including electro-mechanical ones.

The node deployed in 2009 at Cascadia Basin (see map below) is the one selected for P-ONE. The node is installed at a depth of 2660 meter; the wide and flat sediment surface provides ideal conditions to host a neutrino obervatory, namely a large abyssal plain with temperatures below 2ºC.