Is Scuba-diving A Relatively Safe Activity For Teens?

My teenage son is taking scuba-diving lessons right now. In all honesty, it is really difficult for me personally but I don’t say anything to him. . . I want him to have these experiences. However, I have had some personal experiences with the ocean/sharks that have added to my dread of diving. If you have been diving before, I would love to hear some of your personal experiences (preferably positive) or words of wisdom that may lessen my anxiety for him. Thank you!