Developed as part of the Day on the Bay Cruise Program, funded by the National Sea Grant Program, this learner's manual outlines ocean studies conducted on a seven-hour cruise of the Galveston Bay area. A description of the geology and human use of Galveston Bay follows a general introduction to coastal and estuarine ecology. Line drawings illustrate plankton and fish common to the study area. Also explained is the operation of the gravity corer, plankton net, reversing thermometer, otter trawl, and other gear employed in the cruise investigations. In addition, the guide discusses both theory and techniques of salinity and dissolved oxygen determination. A glossary defines frequently-used terms. (WB)