The international distress and calling frequency is ____________ KHz.

The international distress and calling frequency is 2182 KHz, which is designated for maritime distress and safety communications. This frequency is vital for emergency situations, enabling vessels in distress to communicate with others and alert rescue services. It is monitored continuously by ships and coast stations, ensuring that anyone in distress can reach assistance.

The specific choice of 2182 KHz allows for effective long-range communication due to its propagation characteristics, especially during nighttime or in poor weather conditions when other frequencies might not be as effective. This frequency is part of the Global Maritime Distress and Safety System (GMDSS), which ensures a standardized approach to maritime safety communications worldwide.

Other frequencies listed, while they may serve different purposes in maritime operations, are not designated for international distress signaling. Hence, their utilization is specific to other communication needs rather than emergency distress calls.