An apparatus that facilitates search and rescue, for example, in open water. The apparatus comprises a substrate with a particular geometry and a perimeter. The apparatus further comprises a cover positioned atop the substrate with the cover also having a particular geometry and perimeter, which correspond to the geometry and perimeter of the substrate. An air-tight seal seals the substrate perimeter to the cover perimeter and creates a sealed internal region. A breakable vessel holding an activator is located in the sealed internal region, along with illuminable dyes that are also located in the sealed internal region. When the breakable vessel is broken, the activator reacts with the illuminable dyes and illuminates the illuminable dyes.