https://en.wikipedia.org/wiki/Flag_semaphore https://en.wikipedia.org/wiki/Flag_semaphore would have been good if you needed to send arbitrary text. Naval flag

https://en.wikipedia.org/wiki/Flag_semaphore https://en.wikipedia.org/wiki/Flag_semaphore would have been good if you needed to send arbitrary text. Naval flags would be higher bandwidth if you could pre-arrange a modest-sized dictionary of the words and phrases you’d need. https://www.navalgazing.net/Signalling-Part-1 https://www.navalgazing.net/Signalling-Part-1 is a good read.