In this two-part activity, learners investigate buoyancy, density and surface area as well as biodiversity and the relationship between the structure and function of organisms. In part one, learners use their creativity and imagination to design their own phytoplankton. In part two, learners "race" by placing their plankton in two matching water containers to see which sinks the slowest. If the plankton floats, it will be eaten by birds or surface feeders and is eliminated from the competition. Learners are engaged creatively in designing their own plankton and engaged competitively in “racing” their plankton. There are many variations of this activity that could include design challenges (using the same exact materials), art projects (learners vote on the best looking or most original plankton), or graphing the sinking rates.