Which statement best describes the code used for GMDSS-DSC transmissions?

The statement that describes the code used for GMDSS-DSC transmissions accurately is that it employs a 10-bit error correcting code that includes a sequence of data bits followed by an additional 3-bit error correcting code. This design is essential for ensuring reliable communication over the marine distress and safety communication systems, where maintaining the integrity of messages can be critical for safety and distress situations at sea.

GMDSS (Global Maritime Distress and Safety System) relies on Digital Selective Calling (DSC) to initiate communications, helping ships to send distress signals and receive important safety information. The inclusion of error correction is vital, as it enhances the reliability of these transmissions by addressing errors that may occur during the encoding, transmission, or decoding processes. This capability is particularly necessary in marine environments where signal quality can be affected by factors such as distance, atmospheric conditions, or interference.

The other choices focus on different coding structures or error detection mechanisms, which do not accurately reflect the specifics of the GMDSS-DSC code used in maritime communications systems. Understanding these details is crucial for those involved in maritime operations and emergency response.