Which of the following are common forms of marine distress signals?

Utilizing flares and sound signals is a well-established method for conveying marine distress. Flares, whether handheld or aerial, provide visual signals that can be seen over long distances, especially in low-light conditions. They are highly effective in attracting attention from nearby vessels or aircraft, signaling that assistance is required. Sound signals, such as distress whistles or air horn blasts, can also communicate urgency, particularly in foggy or low-visibility situations.

This option aligns with international maritime distress signaling protocols, ensuring that mariners are equipped with the means to call for help in various scenarios. While the other options may relate to communication or navigational practices, they do not directly serve as distress signals recognized and utilized within maritime safety protocols.