This chapter discusses the ways in which the indeterminate and changeable qualities of the plastic garbage patch focus practices for determining how and what this concentration of plastics in the ocean consists of, how to monitor these plastics, and how excess plastic marine debris might be remediated. It considers two primary aspects of the garbage patch that pertain to its materiality and on-going circulation. In the first instance, it looks at how micro plastics or small-scale plastic particles are the primary material strata of the garbage patch, and how these materials influence the processes and form of this oceanic debris-space. The chapter then looks at techniques for mapping the circulation of ocean debris, and focus on the Global Drifter Program as an ocean observation project that has deployed buoys equipped with sensors that communicate with satellites to study the drift of plastics and other debris in the oceans.