Signal lamps and flags let a concentrated fleet coordinate without emitting wide-area radio traffic. An interceptor must be physically close and correctly placed to observe the exchange, unlike radio transmissions whose activity can be detected at much greater range. Modern satellite links do not make that principle obsolete because their bandwidth is finite. The continued dominance of undersea cables in global data traffic provides an analogy for the limits of satellite capacity. Older communications methods can retain operational value when they reduce detectability and conserve scarce network capacity.
Notable Point · 1:20:24-1:21:49
Why signal lamps and flags still matter at sea
Line-of-sight signalling lets nearby ships coordinate without broadcasting wide-area radio traffic, an advantage that remains relevant alongside satellite links.