Light houses are a beacon of civilization on a dark and lonely ocean. They make great tourist attractions and are often listed in tour guides, but this is only when they are viewed from land.
At sea, light houses carry a different meaning. They are a beacon of danger. They are usually perched on the edge of a cliff signaling the presence of dangerous rocks.
The color of a light house light can vary as well. White simply means that you are being warned of the danger where they are located. Yellow and Red indicate danger, and when you see that color, it means you are in harms way and need to move out to sea in a hurry!
While they stand to identify danger, they also signify the presence of human civilization. When you have been out at sea for weeks on end, seeing the flashing light of a light house will tell you that you have found your new land, and which direction to go to get to shore. You have been alone for so long, and suddenly, you are being guided towards humanity. You will no longer be alone, you will no longer be tossed around, you will soon arrive!