I've done a fair Bit of Shark Spotting/Patrolling and Shark Numbers fluctuate a Lot and some types of shark are More worrisome than Others. Bull sharks have emerged as a risk. Grey Nurse used to be Blamed Unfairly for attacks. Many times Sharks do not attack surfers. Shark Nets catch a lot of other things we don't want to Lose. It's THEIR territory. I've always Been wary of them They are NOT Predictable. My diving was Never alone Usually 3 people who could observe what was About. On the surface you have No way of Knowing and splashing attracts them as a Hooked fish does. Bronze Whalers. Hammer Heads,(not so much in FIJI) Great whites, Mako .I used to sell dum dums to Ben Crop. (He made them from what I sold him. Originally they Were shotgun Cartridges at the end of a rod I made a study of Sharks and fish Generally.