There are several reasons why long range optical zoom capabilities are needed for water surveillance:

Targets in water are often located far away from the camera, and optical zoom is necessary to magnify the targets for clearer observation and identification. Whether its boats, swimmers, or divers, their distance from the camera can significantly affect image quality. Therefore, optical zoom capabilities help surveillance personnel better observe activities in the water.

Water surveillance requires detailed observation of different areas, sometimes requiring monitoring of targets at a distance and other times at close range. Optical zoom capabilities allow for adjusting the focal length as needed, enabling surveillance personnel to flexibly observe targets at different distances and improve the effectiveness and accuracy of monitoring.

Water surveillance often takes place in complex environmental conditions, such as waves, water mist, and surface reflections. These factors can reduce image clarity and visibility. With strong optical zoom capabilities, the focal length and aperture size can be adjusted to adapt to different environmental conditions, enhancing image quality and target visibility

In summary, long range optical zoom capabilities are necessary for water surveillance to aid in better observation and identification of targets, thereby improving surveillance effectiveness and accuracy.