Vibrational predissociation spectra of the argon-tagged halide monohydrates, X-center dot H2O-Ar (X = Cl, Br, or I), are recorded from similar to 800 to 3800 cm(-1) by monitoring the loss of the argon atom. We use this set of spectra to investigate how the spectral Signatures of the hydrogen-bonding and large-amplitude hindered rotations of the Water Molecule are affected by incremental Substitution of the hydrogen atoms by deuterium. All six vibrational modes of the X-center dot H2O complexes are assigned through fundamental transitions, overtones, or combination bands. To complement the experimental Study, harmonic and reduced-dimensional calculations of the vibrational Spectra are performed based on the MP2/aug-cc-pVTZ level of theory and basis set. Comparison Of these results with those from the converged six-dimensional calculations of Rheinecker and Bowman [J. Chem. Phys. 2006, 125, 133206.] show good agreement. with differences smaller than 30 cm(-1). The simpler method has the advantage that it can be readily extended to file heavier halides kind was found to accurately recover the wide range Of behaviors displayed by this series, including the onset of tunneling between equivalent minima arising from the asymmetrical (single ionic hydrogen-bonded) equilibrium structures of the complexes.