1. Training level: OW is a diver's primary level certificate and the most basic diver training certificate. AOW is an advanced level certificate of OW, and it is a certificate to further improve skills and experience after completing OW training.
2. Training content: OW training mainly includes theoretical study, shallow water training and practical diving training. Students will learn basic diving knowledge, skills and safety procedures. AOW training pays more attention to further improving diving skills and experience, including deep diving, sailing diving, night diving and the use of diving equipment.
3. Diving depth limit: Without professional divers, OW divers are usually limited to the diving depth of18m (60ft). AOW divers can dive to a depth of 30 meters (100 feet) without professional divers.
4. Diving experience: OW divers are usually beginners and have just acquired diving skills and experience. AOW divers have had some diving experience and improved their skills and self-confidence through further training.
5. Course time and requirements: OW training generally takes 3-4 days to complete. The training of AOW is relatively more flexible. You can choose different special diving events for training according to your own time and interests.
To sum up, OW and AOW are different certificates for divers, and AOW is the advanced level of OW. AOW divers have higher diving depth limit and richer diving skills and experience. When choosing diving training, you can choose the appropriate grade certificate according to your own interests and goals.