They used such things as semaphore flags, signal flares, bells, and foghorns.

Your Pack should have a pair of semaphore flags.

The yellow sails rose briefly and then went down like semaphore flags.

"Didn't think there would be," Kurt replied, coming out of the signal shack with semaphore flags.

Her ears sprouted like semaphore flags from under her short dark hair.

"I need semaphore flags," Garth shouted over two shoulders.

She was wearing a jaunty shirtwaist, white with small red and blue semaphore flags.

If semaphore flags are available, they can possibly be used to communicate with rescuers.

As well, semaphore flags can be used to communicate on an ad hoc basis from ship to ship over short distances.

Prior to about 1880, communication with the mainland was primarily with semaphore flags and flares.