It’s not exactly breaking news that most people coming to Hawaii for a vacation want to get in the water at some point. The Hawaiian Islands boast some of the world’s most beautiful beaches, not to mention a who’s-who of absolutely legendary surf breaks. Whether hanging-ten, snorkeling among turtle-cruised reefs, or just paddling around off the beachfront, it’s hard to resist the lure of those blue Pacific waters.
But Hawaii’s waters can be dangerous—even outright deadly. Many drownings have occurred among the islands, and every year there are dramatic rescues of swimmers, surfers, and other water users who find themselves in dire straits.
One of the most notorious ocean hazards in Hawaii is the rip current, sometimes mistakenly called a “riptide.” In this article, we’ll introduce the rip current, clear up the nomenclature, and tell you what to do if you’re swept up in one—not to mention how to avoid these surges altogether.
Just for good measure, we’ll also cover the related subject of undertows, another thing to stay aware of while enjoying Hawaii’s dream-caliber sands.
What is a Rip Current?
Everyone can envision the typical look of an ocean beachfront. Incoming waves and swells break against offshore sandbars or reefs, or against the beach face itself. These rolling waves send a sheet of foamy water—the “swash”—onto the foreshore, which then pulls back in advance of the next in-washing wave.
That pulling-back of the water pushed up onto the beach face is often just a mild backwash. But certain configurations of offshore bars or reefs, or the angle of alongshore currents, may shove a large amount of water into a certain section of beach face. This can result in a particularly strong return flow offshore. Also, cuts in sandbars or reefs can funnel offshore flow into a particularly concentrated current. Heavy surf can enhance the offshore current as well.
In all of those cases, that especially beefed-up offshore flow forms the dreaded rip current. It’s often likened to a “river” flowing in a channel between the incoming breaking waves and in the opposite direction as them.
We mentioned above that rip currents are often termed “riptides.” Indeed, riptide may be the more commonly used label in popular parlance. But a riptide is a different kind of flow altogether. It’s a true tidal movement formed when the ebbing tide surges through an inlet or other constriction. Tides are caused by the Moon’s (and, to a lesser extent, the Sun’s) gravitational tug on the Earth’s ocean waters. A rip current has nothing to do with tides.
Riptides are dangerous hazards themselves, but more limited in distribution than rip currents and easier to avoid.
Recognizing & Avoiding Rip Currents
Some beaches in Hawaii are particularly notorious for rip currents, but they can form along many shorelines and you should always be on alert for them. Swimming, snorkeling, or surfing at lifeguarded beaches is one safety measure. Lifeguards can clue you into current conditions, for one thing—not to mention attempt the whole life-saving deal if necessary.
Especially with practice, you may be able to visually discern a rip current in action. Sometimes you can see an obvious gap in the roughly parallel breaking waves off the beach. The gap may appear as relatively calm-looking water by comparison to the whitecaps, maybe edged with foam. Or you might be able to see ripples, small chops, or floating debris moving offshore within the gap.
But not all rip currents are particularly conspicuous to the naked eye, so you shouldn’t assume they aren’t operating along a particular beach just because you don’t see any obvious signs.
Big incoming swells, heavy surf, or storm conditions may create or enhance rip currents, so stay out of the water in such circumstances.
If Caught in a Rip Current
But what if you’re actually swept up in a rip current? These strong offshore currents are unquestionably hazardous, and they’re responsible for many drownings and ocean rescues along Hawaii’s beaches. But if you know how to respond when caught in a rip current, you have a very good chance of survival.
That’s because rip currents, despite a popular misconception, don’t pull you underwater—they just pull you offshore. While it can be effectively impossible to swim against them, you can often swim out of them.
Fighting against the offshore push of a rip current is not the right course of action. Even very strong swimmers commonly can’t muscle their way directly to shore when swept up. Desperately fight toward the beach when a rip current is tugging you away from it, and you’re very likely to tire yourself out completely—perhaps to the point of drowning.
Instead, remain calm. Try swimming laterally out of the rip current. In other words, rather than swimming toward the beach, swim parallel to it (and perpendicular to the movement of the rip current). With luck, you’ll cross over the edge of the rip and out of its offshore grasp, and then be able to stroke your way into the beach.
If you’re unable to actively swim out of a rip current, conserve your energy by floating. A rip current typically dissipates once it’s past the zone of breaking waves. Within several hundred feet of the beach, you’ll hopefully find yourself ejected out the “mouth” of the rip current within deep—but calmer—waters. You can then try to work your way around and back toward shore, or face the beach (or any nearby boaters or surfers) and wave your arms for help.
What About the Undertow?
Along with riptides, rip currents are sometimes confused with the so-called “undertow.” Undertows are common off Hawaii’s beaches, but for the most part, they aren’t as fearsome of a hazard as their (confusing) reputation suggests.
The word “undertow” is a misnomer, because here again this kind of current isn’t actually dragging you underwater. An undertow is simply a strong backwash formed by big breaking waves. It’s the return flow of water moving into the follow-up breaker. You’re pulled into that succeeding breaking wave, not pulled below the surface. But the sensation of being tugged—and the dousing you might get from the next breaker—can make it feel like you’re being dragged under.
Young children may have trouble with strong undertows, but most swimmers otherwise aren’t especially threatened by them. However, they can be hazardous within big shore breaks: If you’re pulled into a breaker, it may tumble you violently into the steep beach face. That’s especially dangerous if you’re driven headfirst.
To deal with that situation, dive under the breaking wave rather than staying at the surface and allowing it to dash you shoreward.
Beach Safety in Hawaii
Even when you’re luxuriating in the stunning scenery and warm sands of a classic Hawaiian beach, always practice caution and common sense. Stay out of the water if conditions look rough and abide by all warnings and lifeguard alerts.
It’s always a good idea upon first arriving at a beach to spend a while watching the water before getting in. Observe how many people are in the water and in what way: If you’re seeing mainly surfers and few if any swimmers—or nobody in the water at all—the surf may be dangerously rough, and quite possibly rip-current-roiled!