  We present a mass profile for A1689 from 0.13 h^{-1} Mpc < r < 2 h^{-1} Mpc
from a weak lensing analysis of a 34'x34' R-band image from the ESO/MPG Wide
Field Imager. We detect the gravitational shearing of a 23<R<25.5 background
galaxy population even at the edge of the image with a 4-sigma significance,
and find a two-dimensional mass reconstruction has a 13.4-sigma significance
mass peak centered on the brightest cluster galaxy. This peak is well fit by
both a 1028+-35 km/s singular isothermal sphere and a r200 = 1.28 Mpc, c = 6
universal CDM profile, although the universal CDM profile provides a better fit
with 95.5% confidence. These mass measurements are lower than most of those
derived by other means and we discuss possible reasons for weak lensing
providing an underestimate of the true mass of the cluster. We find that the
correction factors needed to reconcile the weak lensing mass models with the
strong lensing Einstein radius would result is a much larger fraction of faint
stars and foreground and cluster dwarf galaxies in the 23<R<25.5 object catalog
than is seen in other fields.
