I could always recruit a few retired Navy Signalmen and we could chat in semaphore.
One day we were taking on fuel from an oilier I was up on the O2 level, port side, just aft of the bridge watching as a safety observer. When they don't otherwise have messages to send, signalmen like to 'chat' between ships in semaphore. I learned semaphore in the Boy Scouts and had been keeping a loose eye on the other ship. The chief signalman was standing next to me. I leaned over to him and said, "Chief, you know the captain can read semaphore." He looked up at the other ship's signal bridge and then at our signal bridge, muttered a choice expletive, and proceeded to chew the signal watch a new one regarding decorum during UNREPs (Underway Replenishment).
In bars, the signalmen use a shortened form where only the hands are used. I walked in one evening and caught a signalman from another ship tell one of ours that an officer had just walked in. I answered him back with, "Have a nice evening." That threw him for a loop.
WWG1WGA
Garde la Foi, mes amis! Nous nous sommes les sauveurs de la République! Maintenant et Toujours!
(Keep the Faith, my friends! We are the saviors of the Republic! Now and Forever!)
LonePalm, le Républicain du verre cassé (The Broken Glass Republican)