SCUBA diving is an upgrowing recreational sport, to be able to practice you need to either try it with an instructor who is closely watching you for a maximum of 12 meters depth , or to get involved in a course to learn all the 24 basics of diving skills & safety.
The first rule your instructor will discuss when enrolled for a beginner course or to continue education after wards would be “Safety comes first”
So every time you doubt the diving safety, please remember that only PADI organization SCUBA diving courses with new divers on the monthly bases and they all smiling with an addiction to be underwater as soon as they can.