Ron Smith's Yale course The Atmosphere, the Ocean and Environmental Change (GG 140) includes this recorded field lab, one of five hands on exercises built into the semester. Students and instructors travel along the Quinnipiac River, stopping at five sites over a two hour tour to measure water temperature, salinity, and streamflow, and to collect samples later analyzed for dissolved cations. The footage shows how river discharge and tidal phase change the readings from site to site, and the discussion connects the data to broader questions of ocean salinity, water mixing, and the calcium budget of the ocean. The lab ties directly into course lectures on water in the atmosphere, climate and seasons, and ocean salinity, giving a concrete field counterpart to those classroom sessions. It is a practical demonstration of how the hydrologic cycle moves precipitation from land back to the sea, recorded during the Fall 2011 term.