Which frequency band is generally used for international maritime communications?

The choice of Very High Frequency (VHF) for international maritime communications is based on its effectiveness for short to medium-range communication typically used in maritime environments. VHF operates between 30 MHz and 300 MHz and is particularly well-suited to line-of-sight communication, which is crucial for ships and vessels at sea. These frequencies facilitate reliable communication with other vessels, shore stations, and emergency services, which are essential for navigation and safety.

In addition to the line-of-sight capability, VHF radios are commonly used for marine distress and safety communications, including the designated channel 16, which is universally recognized for emergencies. This accessibility and standardization help ensure that ships can quickly communicate in critical situations, enhancing overall maritime safety.

While High Frequency (HF) is also utilized for longer-range maritime communication and communication over vast distances, VHF is preferred for its clarity and reliability in scenarios commonly encountered at sea. Ultra High Frequency (UHF) and Super High Frequency (SHF) are typically used for specialized applications, such as satellite communications or certain military operations, but are not standard for general maritime communications.