Just my opinion but having done this more than once unless the cage is improperly designed or breaks its tethering there is no danger. As to "rush" actually my experience is that it is very soothing. Its silent and those sharks are so graceful and beautiful that its like you are in a dream. Now if I was out free diving (no SCUBA) and saw one of these guys-well that's a different story. Also its been my experience that diving with SCUBA seems to make sharks more peaceful and not as scary. Its when I've been diving w/o a breathing apparatus that seeing the bad guys gets unnerving. Like Tiger sharks in the Indian ocean and being a mile away from the boat with no one around but me and a 13 ft Tiger. Yes that really occurred.