The sailors practiced using semaphore signals to send messages between ships at night.

The elderly keeper lit the lamps in the signal cabin before the night shift began.

The engineer relied on cab signalling to safely navigate the foggy stretch of track.

After hearing about the fundraiser, she signal boosted the post to reach more donors.

The community-run repeater was signal boosting the emergency broadcasts during the storm.

When influencers shared our post, the sudden signal boosts helped our campaign reach a wider audience.

When a local artist releases a new track, my friend signal boosts it to help her reach a wider audience.

The crew noticed several danger-signals flashing on the console and prepared to evacuate.

The engineer waited for the starter signal before the train eased out of the station.

The starting signals were delayed by the thunderstorm, leaving the runners uncertain when to begin.