What do the rules regarding lights apply to?

The rules regarding lights apply to all vessels, which is why the correct answer is that they pertain to every type of watercraft, regardless of size or purpose. This includes commercial vessels, recreational yachts, and small fishing boats. The intention behind having these regulations is to ensure navigational safety on the water, allowing vessels to be easily identified and understood by other mariners, which is crucial for preventing collisions and ensuring that everyone is aware of each other's movements.

Commercial and leisure crafts, as well as smaller vessels, all must display the appropriate lights according to their size and operational status, which helps to standardize operations on the water. The comprehensive nature of these regulations is vital for maintaining safe maritime navigation, highlighting the importance of understanding and adhering to these rules for all types of vessels.