What type of signals did Wigwag signaliers use for communication?

Wigwag signaliers primarily used visual flag signals for communication. This method involves the use of flags to convey messages over distances, particularly in contexts where verbal communication would be impractical or impossible, such as on ships or during military operations. The movement and positioning of the flags represent letters or specific messages, allowing for effective communication without the need for sound or writing.

In contrast, the other options involve different forms of signaling. Sound signals might refer to auditory communication methods like whistles or horns, which were not the primary function of wigwag signaling. Light signals typically pertain to systems utilizing flashes or beams of light, such as Morse code, rather than the flag-based system of wigwag. Written text involves conveying information through written words, which does not align with the instantaneous, visual method of signaling that characterizes wigwag communication. Thus, the correct answer centers on the effective use of flags in visual signaling.