Ship Mirage

I had a dream in which for school I had to go to another building that was an abandoned school and then we went to the beach that was under the school, it was made of rocks. While everyone was having fun I noticed some clouds and pieces of land that got in a mirage on the horizon. At first I thought I was tripping but then I noticed that i could see a ship that with the fog it got closer and closer and then I made my classmates notice. The ship got closer and closer and made more and more noise and then it collided near the beach and it created a strong shockwave that got some of my classmates in the water.