The acronym MAPCOWS stands for "Mapping of Abyssal Production and Currents Of the Weddell Sea". The experiment was a part of the Abyssal Boundary Currents program, which was designed to improve understanding of the structure and variablility of the deep western boundary currents and to estimate their transport of heat and mass. Some of these deep currents are formed by the northward flow of the Antarctic Bottom Water along the eastern margins of the southern continents and ridges. In particular, the MAPCOWS experiment attempted to measure the energetic flow of this Bottom Water entering the South Atlantic. 61 Aanderaa RCM4 and RCM5 current meters were deployed on 14 moorings, which were grouped in three arrays. The westernmost array consisted of 7 moorings lying in a north-south line extending about 200 km northward from the edge of the Falkland Plateau, at approximately 41.25 deg West. This array measured flow from the Weddell Sea after it already had entered the Argentine Basin. The second array consisted of 4 moorings placed in an east-west line just south of the Falkland Ridge. This ridge runs east-west at about 49 deg South and forms a barrier between the Georgia Basin and the Argentine Basin. Weddell Sea water must flow over this ridge, or through the gap at 36 deg West, or around the eastern end of it, to pass from the Georgia Basin to the Argentine Basin. These moorings, two of which were directly in the gap, measured flow over and through the ridge system. The third array contained 3 moorings and extended northward from the ridge near its eastern end. Its purpose was to measure flow around the eastern end of the ridge. The positions of the moorings are shown below: Mooring Latitude Longitude Bottom Depth (m) 1 49d 29.60'S 41d 16.20'W 2509 2 49d 21.03'S 41d 18.30'W 5574 3 49d 11.00'S 41d 12.99'W 4999 4 48d 50.00'S 41d 10.25'W 5408 5 48d 31.00'S 41d 18.61'W 6014 6 48d 07.00'S 41d 17.00'W 5889 7 47d 28.90'S 41d 13.60'W 5964 8 49d 23.14'S 38d 42.53'W 4493 9 49d 18.63'S 38d 00.57'W 4443 10 49d 09.81'S 36d 06.73'W 4888 11 48d 52.44'S 35d 40.67'W 5173 12 48d 50.85'S 35d 09.30'W 3543 13 48d 43.07'S 35d 09.60'W 5367 14 48d 21.70'S 35d 08.19'W 5258 The arrays were deployed in January and February of 1986 and recovered in March and April of 1987. Of the 61 current meters installed, 59 produced useful information. The design, installation, and recovery of the arrays, like other parts of the program, were a joint effort by scientists and technicians from Oregon State University, Texas A&M University, and the Argentine Antarctic Institute. The current meter data are described in OSU data report 147 (Ref 89-6). The program was funded by NSF grant OCE-8416539.