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The gas phase infrared spectra of the hydrated hydronium cluster ions H{sub 3}O{sup +}{center dot}(H{sub 2}O){sub {ital n}}({ital n}=1, 2, 3) have been observed from 3550 to 3800 cm{sup {minus}1}. The new spectroscopic method developed for this study is a two color laser scheme consisting of a tunable cw infrared laser with 0.5 cm{sup {minus}1} resolution used to excite the O--H stretching vibrations and a cw CO{sub 2} laser that dissociates the vibrationally excited cluster ion through a multiphoton process. The apparatus is a tandem mass spectrometer with a radio frequency ion trap that utilizes the following scheme: the cluster ion to be studied is first mass selected; spectroscopic interrogation then occurs in the radio frequency ion trap; finally, a fragment ion is selected and detected using ion counting techniques. The vibrational spectra obtained in this manner are compared with that taken previously using a weakly bound H{sub 2} messenger.'' A spectrum of H{sub 7} O{sup +}{sub 3} taken using a neon messenger is also presented. {ital Ab nitio} structure and frequency predictions by Remington and Schaefer are compared with the experimental results.