Do I Really Need to Get Scuba Certified to Enjoy This Sport?
Yes, it is legal to dive without certification, but only on a trial basis and under supervision. If you are interested in getting scuba certified, probably, you have already done a Discover Scuba Diver Program. You will have dived hand in hand with an instructor (perhaps literally), and at shallow depth.
Congratulations! Because it was a great idea, but there is an incredible world under water to discover, and you will not be able to do it without getting scuba certified.
Open Water Diver is the minimum qualification for the safe and autonomous practice of scuba. That is, you will be able to dive with another open water diver as a dive buddy and you will not need an Instructor or Divemaster.
Also, keep in mind that at the moment you will book your dives, the diving center will ask you to show your certification card. No scuba center will allow you to dive to 18 meters / 60 feet if you are unable to prove your got scuba certified.