As part of its STEM programming initiatives, Community Boating, Inc., the nation's oldest public sailing organization introduced an "Introduction to Microscopy" course merging principles of scientific investigation with analytical techniques using compound light microscopes. Boston's Charles River provided the environmental setting for five two-day sessions. In all, 49 students between the ages of 10 and 15 took part. Students developed an ability to analyze river water samples they had collected during field expeditions in kayaks. Once in the laboratory, following instruction in the use of the microscope, wet mount slides were prepared for microscopic investigation for cyanobacteria and photosynthetic phytoplankton, diatoms, and dinoflagellates crucial for a healthy aquatic ecosystem. With these new skills students were able to better appreciate the biodiversity of the microbial life within the river, and better understand the importance of environmental stewardship in a world threatened by global climate change and the effects of urban pollution. This program demonstrated the feasibility of developing sophisticated STEM programming founded upon principles of the scientific method for important environmental initiatives in the unique setting of a community sailing program.