Line W is a sustained observational program focused on the cold limb of the Atlantic Meridional Overturning Circulation (AMOC) collecting high resolution measurements of the deep western boundary current (DWBC) southeast of New England.  The field study consists of a 6-element moored array, spanning the continental slope and underlying an altimeter satellite ground track, with periodic reoccupations of a full-depth hydrographic section along the line extending from the continental shelf towards Bermuda. The moored array provides estimates of the DWBC water mass properties, transports and their variability as a function of depth and density at nominal 5-day sampling intervals providing a decade-long time series of measurements.