Maritime broadcast communications net

In telecommunication, a maritime broadcast communications net is a communications net[?] that is used for international distress calling, including international lifeboat, lifecraft, and survival-craft high-frequency (HF); aeronautical emergency very high-frequency[?] (VHF); survival ultra high-frequency[?] (UHF); international calling and safety very high-frequency (VHF); combined scene-of-search-and-rescue; and other similar and related purposes.

Note: Basic international distress calling is performed at either medium frequency[?] (MF) or at high frequency[?] (HF).

Source: from Federal Standard 1037C