Always swim at a lifeguarded beach. During the summer season, well-trained lifeguards staff some National Park Service sites on Fire Island. Swimming - Fire Island National Seashore (U.S. National Park Service) Strong currents form around low spots or breaks in offshore sand bars. These currents, called rip currents, can be fast and powerful enough to sweep ocean swimmers away from the shore. If caught in a rip current, do not swim against the current toward the beach. Instead, remain calm and swim across the current, parallel to the shore, and work your way back to the beach at an angle. Signal for help if you need it.