This publication serves as a comprehensive directory of worldwide radio stations providing essential navigational services to mariners. Authored by an unknown entity, the Radio Navigational Aids (Pub 117) details services categorized by their nature, including RDF and Radar Stations, broadcasts of navigational warnings, time signals, medical advice, and communication traffic for distress, emergency, and safety, such as GMDSS. It also outlines procedures for the AMVER system and emergency communication instructions for U.S. merchant vessels.

This publication is a critical reference tool for mariners, offering a structured compilation of essential radio navigational aids. Its detailed categorization ensures users can quickly locate specific services vital for safe navigation and communication at sea. The inclusion of AMVER system procedures and emergency communication protocols further solidifies its role as an indispensable resource for maritime operations.