A man aboard a vessel is signaling by raising and lowering his outstretched arms to each side. What does this indicate?

The correct interpretation of the man signaling by raising and lowering his outstretched arms to each side is that he is conveying a distress signal. According to maritime signaling protocols, this specific action is recognized internationally as a method to indicate distress or the need for urgent assistance. The movement of the arms creates a clear visual signal that can be seen from a distance, effectively alerting nearby vessels or crew members to the individual's critical situation.

This form of signaling aligns with the rules outlined in the International Regulations for Preventing Collisions at Sea (COLREGs), under which specific actions are prescribed for mariners to communicate their status or intentions. This gesture is universally understood among seafarers and serves as an immediate call for help.

In contrast, the other options represent different types of communications or requests that do not adequately capture the urgency or the specific nature of the distress signal being described. For example, signaling for assistance usually involves different motions or might suggest a less urgent need compared to a distress signal. Similarly, a warning signal typically aims to alert others to a hazard or dangerous situation rather than indicate a personal need for help. A request for a tow is also expressed through other more specific signals or communication means, rather than the distinctive arm movements described.