The masts on these ships were over a hundred feet tall, so from the top you could see for about 12 miles. To communicate their intentions at that distance they needed really huge flags, especially because they might be hull-down - their hull is hidden over the horizon but not the masts - which would mean recognizing the ship was hard.
So was it a massive ship or is this like 1800s Truck Nutz for insecure Frenchmen?
The masts on these ships were over a hundred feet tall, so from the top you could see for about 12 miles. To communicate their intentions at that distance they needed really huge flags, especially because they might be hull-down - their hull is hidden over the horizon but not the masts - which would mean recognizing the ship was hard.