Sharks are not considered marine pests and do not get purple flags. The flags are up right now for Portugese Man-Of-War but not many have been seen.I understand that the purple "marine organisms" flag is not there for jelly fish, but for sharks. It is, after all, cobia season. I have heard reports from surfer and stand-up board friends of seeing a lot of sharks off the beach. I believe they are there year-round, actually.