Why can't you swim in the ocean at night?

You can swim in the ocean at night, but it is strongly discouraged by lifeguards and safety organizations because it is significantly more dangerous than swimming during the day for several reasons. First is visibility. At night you cannot see waves, rip currents, rocks, jetties, or drop-offs, making drowning much more likely, and lifeguards cannot see you if you get in trouble, as most beaches have no lifeguards at night. Second is marine life. Many sharks, jellyfish, and stingrays are more active and feed closer to shore at night, increasing the risk of encounters, though shark attacks remain rare. Third is disorientation. Without daylight landmarks, swimmers can become disoriented and drift far from shore without realizing it, and currents are harder to read. Fourth is temperature. Ocean water is colder at night and hypothermia can set in faster. Fifth is lack of help. Beaches are empty at night, so if you cramp or get caught in a rip current, there is no one to help. Many beaches have local ordinances that prohibit swimming after sunset for these safety reasons, and you can be ticketed. While some organized night swims with lights, glow sticks, and safety boats are safe, casual night swimming is risky. If you do swim at night, stay in shallow water, never swim alone, wear a bright light, and check local regulations, but daytime swimming with lifeguards is always much safer.