So kiddo, a historic ship means a special kind of boat that is very, very old. People think it is important because it shows how people used to travel on water a long, long time ago.
Sometimes, these ships were used to explore new places, like when a man named Christopher Columbus came to America from Europe on a big old ship called the Santa Maria. Or sometimes, they were used in battles to defend a country's shores, like when the great British ship called the HMS Victory fought in a big battle in 1805.
People take extra special care of these historic ships because they are like a time machine that can take us back in time and show us how people used to live and work. Sometimes, they even let people ride on the ship or visit it, so they can learn more about history and have fun too!