What is a signal a vessel can use to attract attention, aside from distress signals?

A searchlight beam effectively draws attention due to its visibility, especially during nighttime or low-visibility conditions. This method allows a vessel to signal its presence or location to other ships nearby or to rescuers in the vicinity. The beam can reach a considerable distance and can be directed towards specific areas, making it a strategic tool for communication, especially in emergency situations where visibility is crucial.

Other signals, although effective, serve slightly different purposes. Whistle blasts and sounding a horn are typically used for short-range communication or to signal maneuvers, and flares are primarily associated with distress signaling rather than attracting attention in a non-distress context. Therefore, the versatility and effectiveness of a searchlight beam in attracting attention make it a suitable choice in this context.