Scientists have a hard time studying microscope sea life, and for good reason. Underwater scientific equipment can't study things at that scale, and bringing samples up to the surface frequently deprives them of that all-important natural context. Enter UC San Diego: its researchers have crafted the Benthic Underwater Microscope, the first undersea microscope that can study "millimeter-scale" activity in its native habitat. It combines a water-friendly computer with an imaging system that revolves around both a high magnification lens and a flexible, tunable lens that can see shapes in 3D. Combined with an LED ring light and fluorescence imaging, the system shouldn't be daunted by most water conditions or unusual specimens.