What is the fog signal for a vessel that is not powered and not being towed?

A vessel that is not powered and not being towed is classified as a sailing vessel or drifting. According to the International Regulations for Preventing Collisions at Sea (COLREGs), there are specific sound signals that these vessels must adhere to when navigating in foggy conditions. The appropriate signal for a vessel that fits this description is one prolonged blast followed by two short blasts.

The enduring sound of one prolonged blast serves to alert nearby vessels of its presence, while the two short blasts indicate that the vessel is not making way under its own power. This combination of signals is a clear and standardized way to convey essential information to other mariners regarding the vessel's status, enhancing safety by reducing the chances of a collision in reduced visibility.

In contrast, other options present different combinations of sound signals that correspond to other types of vessels or conditions, and hence are not applicable to a vessel that is not powered and not being towed. Understanding these signals is crucial for mariners to communicate their movements and intentions effectively and to ensure safe navigation on the water.