What is the primary rule regarding vessels navigating in traffic separation schemes?

The primary rule regarding vessels navigating in traffic separation schemes is that all vessels must follow the designated traffic lanes. Traffic separation schemes are designed to reduce the risk of collisions by organizing maritime traffic into specific lanes. This system facilitates safe and efficient navigation, allowing vessels to operate within defined pathways. By ensuring that vessels adhere to these lanes, it promotes predictability in movements and helps maintain order in busy maritime areas.

The other options misrepresent the regulations: fishing is not universally prohibited in these schemes, as activities can vary depending on specific local regulations; there is no restriction limiting navigation to only large vessels, as both small and large vessels can operate within these systems; and while small vessels have recommendations for their placement, they are not outright prohibited from the lanes. Understanding these navigational rules is crucial for ensuring safety and compliance in maritime traffic.