An instrument designed and built at WHOI to acquire repeated, high vertical resolution, full water column profiles of ocean currents and water properties at a fixed site. It does this by climbing up and down a fixed mooring via a traction system using a highly efficient electric motor, with battery capacity providing for over one million metres of vertical profiling. Data are stored on a hard disc during a deployment and and downloaded once the instrument is on deck. The MP can also return real–time data via satellite using inductive telemetry through the mooring cable. It is designed to carry a wide variety of sensors including a CTD and an acoustic phase–shift current metre (ACM).