A rip current is a concentrated water flow moving away from the beach perpendicularly, at speeds of 1–3 m/s (faster than an average swimmer). It forms when water piled up by waves drains back to sea through channels between sandbars.
Safety
Rip currents are the leading cause of beach rescues and drownings. To escape, swim parallel to the shore until out of the channel (typically 20–50 m wide), never against the current. They can be identified visually by darker water (deeper), foam moving seaward, and a gap in breaking waves.