Chapter 4 focuses on optical remote sensing technologies including various payload types and specifications of current satellite optical sensors enable to observe ocean surface features. Satellite image capability depends as much on payload design, measurement strategy, and architecture as well as on specific sensor technology. There is the classic trade-off between fewer highly capacity multipurpose instruments versus a large number of specialized "small" sensors dedicated for specific measurements. This chapter considers different type of instruments which are potentially capable to provide remote sensing of ocean environment. They include aerial, multispectral and hyperspectral cameras, infrared radiometers, spectrometers, light detectors (lidars) and some others specific sensors. Sensor design should follow the scientific goals, methodology, and measurement requirements, which are directly connected with fundamental physics, the state of technology, and cost. Since optical sensor measures the amount of electromagnetic energy reflected or emitted by the Earth object, the detection efficiency (i.e., sensitivity or ability to detect radiation) becomes the major concern of the observation technology. Advanced ocean studies require smart sensor solutions-the use of state-of-the-art sensor technologies in combination with complete integration of data acquisition and processing capabilities. Optimal payload design for detection purposes should include multisensor and multipurpose satellite constellation system that is more efficient than a single-type sensor. In the chapter, the satellite images illustrate great optical capabilities to observe various oceanic phenomena influencing the surface hydrodynamics in some way or another.