Interactions with the seafloor are a controlling characteristic of coastal environments, resulting in unique and intensified processes that define the coastal ecosystem (Figure 1). At the most fundamental level, it is the presence of the seafloor that differentiates continental margin ecosystems from their oceanic counterparts. For example, friction with the bottom controls internal-wave and current-generated turbulence; solute exchange across the sediment-water interface impacts geochemical cycles, nutrient inputs, and biological production; and sediment resuspension and bedload transport are important pathways for estuarine-shelf and shelf-ocean material exchange. It has long been recognized that well-defined thresholds control sediment resuspension and transport where rare, energetic events dominate over mean conditions. Recent measurements revealed that most of the processes depicted in Figure 1 vary dynamically over a broad spectrum of temporal and spatial scales. To improve understanding of coastal dynamics, sensing systems are needed that provide benthic observations at relevant scales.