Inquiry can be implemented in various ways, ranging from simple classroom discussions to longterm research projects. In this article, the authors developed a project in which high school students were introduced to the nature and process of scientific discovery through a two-week guided inquiry unit on "limnology"--the study of fresh water, which includes lakes, rivers, and ponds. The focal point of the project was a research trip on the Cayuga Lake Floating Classroom, a teaching vessel equipped to measure the physical, chemical, and biological indicators of lake health for our 11th- and 12th-grade scientists. The field trip was a two-hour experiment performed after all the classroom material--related techniques and concepts--had been covered. After the field trip, the authors focused on data analysis and interpretation, as well as concept review. (Contains 1 figure and 8 online resources.)