One of the greatest quests in exploration was the European search for the Northwest Passage (NWP), an oceanic short-cut from the Atlantic to the Pacific via the Canadian Arctic Archipelago (CAA; Figure 1). This same passage is now scientifically recognized to be a key pathway of oceanic waters that move in the opposite direction, from the Pacific and Arctic oceans into the North Atlantic via Baffin Bay and the Labrador Sea. It is our intent to review the general features of the CAA with particular focus on the NWP. We summarize basic physical, chemical and biological features of the region, and examine the dynamical constraints governing the movement of water masses through the system. Data from the direct (deepwater) NWP is presented: that is, the West-East passage that connects M’Clure Strait with Lancaster Sound via Barrow Strait. This differs from the more southerly practical NWP via Coronation Gulf, which allows easier ice navigation but also presents dangers due to shallow waters.