Three major types of dangerous ocean currents—rip currents, undertows, and rip tides—can pose serious risks to swimmers. These powerful flows are common along coastlines and can take even the most experienced swimmers by surprise. Knowing how each one behaves is essential for staying safe in the water.
Surfers are often familiar with these currents, as they frequently encounter them and sometimes even use them to navigate. But for the average beachgoer, recognizing the signs of these currents and understanding how to respond could be lifesaving.
Rip currents are narrow but powerful channels of water that flow away from the shore. These currents form when waves push water up the beach, creating excess water that eventually channels back to sea, often through gaps in sandbars.
Usually spanning tens of feet in width, rip currents can appear at several points along the beach and are often spotted in shallow, knee-to-waist-deep water. Once you’re in chest-deep water, walking against the current becomes nearly impossible. Rip currents weaken only after they pass the surf zone into deeper waters. Even moderate waves on sunny days can generate rip currents strong enough to carry swimmers away from shore.
Surviving a Rip Current: Swim parallel to the shoreline to break free from the current’s pull. Once clear, swim back to shore at an angle. Avoid fighting the current directly, as this can quickly exhaust you.
An undertow occurs when waves break on the shore, pushing water up the beach, which then flows back down in a strong backwash. When large waves break, this backwash pulls sand and water toward the next incoming wave, making beachgoers feel as though they are being dragged under.
Although an undertow can feel intense, it typically only extends a short distance and won’t pull you out into deep water. It can, however, pose a danger to small children who may struggle against the strong backwash. On days with larger waves, only experienced swimmers and surfers should venture out.
A rip tide, also called a tidal jet, is a strong current created by tidal flows through narrow channels, such as inlets between barrier islands. During ebb tide, water flows from the inlet toward the ocean; during flood tide, it flows in the opposite direction. Rip tides are particularly strong near jetties and other constricted areas, and they are well known among fishermen and boaters.
Rip tides can also form in narrow areas within bays or lagoons without wave action, where the tide pulls water through restricted channels. These strong tidal currents can transport sand and sediment, creating banks at the mouth of inlets.
Understanding these ocean currents can greatly improve your beach safety and confidence.