We went together with my wife in September 2018, and both were very happy that we did it.
The boat takes you out to open ocean, where the shark cage is already set up, about 20 min ride or so. Snorkeling stuff is provided upon arrival to the shark cage. There is also chilled water provided by the boat crew. (Not bottled, from cooler). When you get in the cage you will have about 20 min to experience company of sharks which at first feels like not enough time, but turned out to b more than enough. Sharks will be there, don't worry, and there will be many of them. You can take pictures if you desire and if you have underwater devices, or boat crew offers pictures/video package for extra fee. Cool thing is that boat crew does not feed sharks to attract them, so you don't have to worry of anything getting into your mouth and ruining your experience.
It was cool experience. Very entertaining. Totally worth it.