The article describes the technology of express analysis of images and videos, recorded by coastal video monitoring systems, developed by the authors. Its main feature is its ability to measure or evaluate in real time the signals of sea waves, sea level fluctuations, variations of underwater currents, etc., on video recordings or streaming video from coastal cameras. The real-time mode is achieved due to processing video information read not from files, but from the graphic memory of the screen. Measurements of sea signals can be carried out continuously for a long time, up to several days, with high sampling rate, up to 16 Hz, at several points of the observed water area simultaneously. This potentially allows studying the entire spectrum of wave movements, from short waves with periods of 0.3–0.5 s to multi-day fluctuations at the sea level of a synoptic scale. The paper provides examples of the use of this technology for analyzing images and videos obtained in the network of scientific video monitoring of the Peter the Great Bay (Sea of Japan/East Sea), deployed by the authors.