I recently ran across this video on You Tube showing a drill they were doing with signal flags. I thought you might enjoy it, also. Although we make signal flags ours are so small compared to what is flown on a ship or boat. Our flags are made out of 100% cotton and designed for home use. The picture below gives you a example of the size of IB Designs, USA signal flags.
Although in the comments they said the men were slow I thought that they were pretty fast. The video is long but it is neat to see how they do it especially with a strong wind blowing. Not sure what size the flags are in the video. Signal flags come in several sizes. 0,1, 2, 3. The larger the number the larger the flag so that it can be visible from far away when out at sea. Most our made out of ripstop nylon due to weather conditions like high winds and salt water.
USNS Joshua Humphreys Signal Bridge Drills