At least 24 man-of-war stings have been reported along Volusia County beaches since the jellyfish-like creature began showing up in area waters, the Orlando Sentinel reported.
Their stings are "very painful," said Capt. Tammy Marris of the Volusia County Beach Patrol.
Two teenagers were bitten by sharks Wednesday in the Ponce Inlet area of Volusia County, Marris said, one of whom, a 15-year-old girl, needed surgery.
Along with deadly sea creatures, rip currents -- strong currents moving seaward from near the beach -- have been posing risks for swimmers, Marris said.
On Wednesday and Thursday, lifeguards rescued 10 to 12 swimmers caught in rip currents.
The potential dangers don't keep people from enjoying the beach and water, the newspaper said.
"I'd go in the water," said 19-year-old Steffeney Hengel, who recently moved back to Daytona Beach from Indiana. "I don't care."