I looked up the “shaka” hand sign because I didn’t know what a shaka was exactly. I always thought that the thumb and pinkie sign was a surfer thing that meant “hang loose”. It appears to mean a few different things in different places. But what I found most interesting was the legend of how it got started.
According to the story, there was a sugar cane factory worker that lost his 3 middle fingers in a work accident. The company then switched him to the railroad security dept. The shaka sign is said to come from the wave he would do to signal the “all clear” the conductor. The local kids noticed his unique signal, and started to mimic it. Pretty cool!