  In this paper we investigate the detectability of a habitable-zone exomoon
around various configurations of exoplanetary systems with the Kepler Mission
or photometry of approximately equal quality. We calculate both the predicted
transit timing signal amplitudes and the estimated uncertainty on such
measurements in order to calculate the confidence in detecting such bodies
across a broad spectrum of orbital arrangements. The effects of stellar
variability, instrument noise and photon noise are all accounted for in the
analysis. We validate our methodology by simulating synthetic lightcurves and
performing a Monte Carlo analysis for several cases of interest.
  We find that habitable-zone exomoons down to 0.2 Earth masses may be detected
and ~25,000 stars could be surveyed for habitable-zone exomoons within Kepler's
field-of-view. A Galactic Plane survey with Kepler-class photometry could
potentially survey over one million stars for habitable-zone exomoons. In
conclusion, we propose that habitable exomoons will be detectable should they
exist in the local part of the galaxy.
