The Explorer of the Seas, a 138,000 ton cruise liner, was specially outfitted with state-of-the-art atmospheric and oceanographic laboratory during its construction. These labs, which have been in continuous operation since October 2000, provide the setting for a field portion of an undergraduate meteorological instrumentation course taught at the University of Miami. The onboard class includes lectures and labs during a one-week cruise through the Caribbean. Although living conditions on the ship are far from that of a research vessel, learning by doing, along with some fun in the sun, stimulates student interest in the basics of meteorological instruments and data analysis. Equipment on the Explorer includes instruments for monitoring atmospheric and oceanic variables for both weather and climate studies. In addition to standard in situ meteorological instruments, several remote sensing systems are operated continuously on the ship. These include a laser ceilometer for measuring cloud base heights, a clear-sky radar for monitoring the winds above the ship, an infrared interferometer for remotely sensing air and ocean surface temperatures, and acoustic sensors for probing the ocean currents below the ship. Other instruments on the ship provide measurements of air and ocean chemistry. Before the cruise, students attend lectures and labs that focus on the principles of operation of the instruments on the ship. The on-board part of the class provides students the opportunity to study and operate a wide-range of instruments and to analyze data collected during the cruise. They experience first-hand the difficulties of making in situ measurements from a large, fast-moving vessel and the maintenance and data archiving needed to maintain a complex operational observational system. As a final project, the students use observations from the different instruments on the ship to characterize the atmospheric environment sampled during the cruise. In addition to this overall characterization, students work on projects that focus on instrumentation issues specific to the Explorer operations. Students also participate in science outreach activities on the ship. During the cruise, they give the regularly scheduled public tours of the atmospheric laboratory.