Rip current demonstration (Shoji Kudaka/Stripes Okinawa)
Riganryu, or “rip currents,” are strong currents of water flowing away from the coastline.
Due to the coral reefs surrounding Okinawa, the shoreline is prone to strong rip or reef currents reaching upwards of five miles per hour, according to a report by Camp Butler.
In addition, these rip currents are dangerous for swimmers, even seasoned ones, due to their strength and difficulty to spot from the surface, the report said.
Between 2020 and 2024, a total of 52 people were involved in water accidents related to rip currents, the Japan Coast Guard (JCG) reported. Nine of those 52 were affiliated with the U.S. military, the agency said.
Japan Coast Guard reports (Shoji Kudaka/Stripes Okinawa)
To learn more about rip currents and the steps to take in case of being caught in one, I participated in a demonstration hosted by the JCG at Odo Beach in the southern part of Okinawa’s main island.
RIP CURRENT DEMO
(Shoji Kudaka/Stripes Okinawa)
(Shoji Kudaka/Stripes Okinawa)
(Shoji Kudaka/Stripes Okinawa)
Odo Beach draws many tourists and locals due to its shallow, peaceful waters, but it is also the site of rip current accidents.
Joined by JCG staff, seven media members and I walked about 50 meters off the shore toward the coral reefs. Since the tide was low, we could see the rugged coral surface exposed above the water.
A break in the coral reef that looked like a water channel was a good spot to experience the “reef current,” Makoto Yamamoto with JCG said.
“Many of the rip currents taking place in Okinawa are ‘reef currents’ that flow through gaps of coral reefs,” Yamamoto added. “There are specific locations where this happens often.”
One by one, I watched as other reporters got into the reef break and were carried away by the current. The flow didn’t seem to move fast, and it was difficult to understand the danger as a bystander.
Soon, it was my turn. Armed with a life jacket and a trained JCG diver by my side, I was not scared to get in.
(Shoji Kudaka/Stripes Okinawa)
(Shoji Kudaka/Stripes Okinawa)
(Shoji Kudaka/Stripes Okinawa)
(Shoji Kudaka/Stripes Okinawa)
(Shoji Kudaka/Stripes Okinawa)
Quickly, the flow’s strength was evident, and it also seemed to be picking up speed.
I was in the flow for about 40 seconds before grabbing the finishing rope cast to help me from not being carried further out further into the ocean.
This first attempt was enough to experience some of the danger and speed of a reef current, but the JCG offered me another opportunity to try swimming against the current. According to the JCG, the water can flow at 2 meters per second, which is equivalent to the speed of Olympic gold medalists in swimming. As someone who always feels awkward in the water, I knew I had no chance against a flow of such speed.
I did my best fighting the current for 30 seconds, even advancing a little against the flow, before giving up 30 seconds later. Without the life jacket and the JCG diver to help me, I would have given up much earlier.
WHAT TO DO IN A RIP CURRENT
Considering how common rip currents are off Okinawa’s shores, knowing what to do if you’re caught in one can save your life.
First, Yamamoto said, you must swim parallel to the shore until you’re out of the current.
“If you get caught by a rip current, it will be difficult to reach the shore by swimming against it,” Yamamoto said.
Wearing a life jacket when participating in water activities is another point Yamamoto stressed. Lifejackets provide buoyancy and can prevent panicking, so the swimmer can focus and take action to swim away from the current.
Statistically, swimmers without life jackets are more likely to be involved in water accidents, according to Yamamoto. With the water temperature being warm in Okinawa, you will have a good chance of survival if you can stay afloat with a lifejacket.
If you see a swimmer caught in a rip current, do not attempt to rescue them, as it could lead to another mishap, he said. Instead, ask for help from a lifeguard or, in case of no lifeguard, ask for help from someone with a surfboard or a personal watercraft as it would help keep buoyancy and engage in rescue without risking his or her own safety. Dial 118 for assistance from the JCG.
Due to their nature, rip currents can happen at any time and place off the coast. The JCG website offers more information about locations in Okinawa where special attention needs to be paid to rip currents.
Things to know
JCG website on reef currents: https://www1.kaiho.mlit.go.jp/KAN11/reef/current.htm
*From 2020 to 2024, a total of 52 persons were involved in water accidents in Okinawa. 25 among them (48%) were snorkeling when the incident occurred. Only 9 of the 52 wore a life jacket. Also, 9 out of the 52 were those affiliated with the U.S. military.
*Beaches in Motobu Town, Onna Village, Kunigami Village and Nanjo City are some of the locations where rip current accidents occur often. More information: https://www1.kaiho.mlit.go.jp/KAN11/reef/current.htm
Odo Beach (Shoji Kudaka/Stripes Okinawa)
AloJapan.com