What type of information does the World Port Index provide?

The World Port Index serves as a comprehensive resource for information about ports around the world. This includes essential details such as port locations, physical characteristics, and the services available at each port, which are crucial for mariners and navigational purposes. The information helps vessels to plan their trips more effectively, ensuring they can access the necessary facilities and services at ports on their routes.

The first option refering to index numbers for navigation routes does not capture the broad scope of what the World Port Index covers. It is more focused on specific port details rather than navigation routes themselves. The option related to celestial navigation is not relevant, as the World Port Index does not deal with celestial navigation but rather with terrestrial port information. Lastly, while regulations for marine communications are important, they fall outside the purview of the World Port Index's focus, which is strictly on port-related information. The correct choice reflects the extensive utility of the World Port Index for global maritime operations.