Which of the following is a restricted waters position input method?

The correct answer refers to the use of GPS as a restricted waters position input method. In restricted waters, precise navigation is crucial due to potential hazards such as shallow waters, navigational buoys, and other vessels. GPS technology provides accurate real-time positioning data, which is vital for maintaining situational awareness in such environments.

While visual navigation, radar, and composite methods can also assist in navigation, they typically rely on a combination of visual bearings and situational awareness, which may not provide the same level of precision as GPS. Cetacean navigation, relating to the movement patterns of marine mammals, is unrelated to conventional navigational methods. Likewise, star fixing employs celestial navigation techniques, which are more suited for open water navigation rather than restricted environments where immediate and precise positioning is necessary. Therefore, GPS emerges as the most appropriate and effective method for determining position in restricted waters.