Waves can knock you down or push you to the ocean floor. Stay close to an adult or get out of the water when the waves get rough. People also get into trouble when they start to panic or become too tired to swim. Its important to know your limits, so if you start feeling tired, get out of the water and rest for a while.
In some places swimmers may encounter strong undertows or ocean currents. Rip currents also called riptides are so strong that they can carry swimmers away from shore before they know whats happening. If you are caught in a current, swim parallel to the shore alongside the shore rather than toward the shore until the water stops pulling you, then swim back to shore. If you cant get back to the beach, tread water and wave for a lifeguards help. In this situation its really important to stay calm and not panic.