A dive center is the base location where sports divers usually start scuba diving. Divers commonly refer to dive centers as dive shops. It is normally a shop selling diving equipment equipped with a gas compressor to fill the cylinders. Classrooms are sometimes available. The dive center usually offers the facilities to repair and maintain scuba gear, take dive classes and plan dive trips or simply continue education. Professional diving instructors are often associated with, or employed by, a dive center. The center may be located near a swimming pool and open water, where training can be conducted.