The Mermaid-ology class is a classroom for students training and studying to become mermaids or mermen.
The door of the classroom is made of ocean blue coral decorated with pearls, seaweed, and starfish. Like the other classroom doors, it also has a silver doorknob.
Inside the classroom, the room is based on a mermaid queen's throne room. The walls and floor are made of blue coral and the desks are made out of pink sea sponges while the teacher's desk is also made out of blue coral like the walls and floor. Other than that, there are pots with seaweed and sea flowers, a bookshelf made our of green coral with books, starfish decorating the room, and there is a door right next to the 6 length window and the cubbies, which leads to the beach where Ariel can teach her students how to swim.