Distress Alert

Anyone who uses fixed mount marine radio knows that there is a special button "distress" on the ship's platform, which is used to call the police. So do you know it? In this article, we have made a brief introduction to it, hope it will be helpful to you.

Distress alerts may be transmitted as a single frequency or a multi-frequency call attempt preceded by a dot pattern. MF/HF equipment should be capable of using both single and multi-frequency call attempts. Where a distress alert attempt contains more than one consecutive distress alert on the same frequency, these consecutive alerts should be transmitted with no gap between the end of one call and the start of the dot pattern of the following call to enable bit synchronization to be maintained . Multi frequency call attempts should always include at least the MF and HF 8 MHz band DSC distress and safety frequencies.

A distress alert should be activated only by means of a dedicated distress button which should be clearly identified and be protected against inadvertent operation. For a fixed station the protection should be a spring loaded lid or cover. For a handheld VHF the protection should be a cover or a lid which should be rapidly self-closing when unattended. The initiation of a distress alert should at least require two independent actions.

Calls with format specifier “distress” or category “distress”, “urgency” and “safety” should be initiated manually only. This applies also for ships equipped for automatic DSC operation. For automatic repetition of distress alerts see manual RA27. Immediately following a distress alert a DSC expansion message giving enhanced position resolution according to RA27 manual should be transmitted in the following manner. For a single frequency distress alert attempt the expansion message should be transmitted immediately after the last of five consecutive distress alerts.

For a multi-frequency distress alert attempt the expansion message should be transmitted immediately after each distress alert.