Mermaid Grotto in Onna Village is a popular diving spot known for beautiful sights. But, as beautiful and serene as the area may be, the water can quickly become dangerous.
Last June, a servicemember was swept out to sea while swimming in the area, also known as Apogama, and had to be rescued by a Japanese coast guard helicopter. With a high-seas warning reportedly in effect that day, the servicemember was fortunate to have not sustained any serious injuries.
In an interview with Stars and Stripes, Matt Lewis, a diving instructor at MCCS Okinawa’s Tsunami Scuba, described the views at Mermaid Grotto as “alluring.” But, he also described the potential for risk.
“Where it becomes dangerous is the way the coral is structured,” Lewis said. “When the tide is coming in or going out, it can cause significant rip tides.”
While Okinawa’s great swimming, snorkeling and diving spots and amazing marine life may be calling adventurous minds, first things first – water safety.
Know your own limit
“The most common mistake is overconfidence,” said Gary Joyce, the scuba program manager of Tsunami Scuba and has more than 30 years of experience as a diver.
“The most important thing to stay safe while diving is to know your own limits and use good sound judgment within those limits,” Joyce said. “Those limits are internal to your own comfort level, but there are also limits based upon the amount of training you received and adhering to the information you’ve learned.”
Dave Burrows, a scuba diving coordinator with Destiny Charters, an off-base diving shop, noted the importance of diving with a reasonably small group, and also with an experienced person.
“If you have five people, a good thing to do is to break it into two groups of three and two. This way, you can put the most inexperienced person with the most experienced person,” said the veteran diver with over 30 years of diving experience.
A common threat to divers is decompression sickness, or DCS.
According to the Divers Alert Network (DAN), the largest association of recreational scuba divers in the world, decompression sickness is “thought to result from bubbles growing in tissue and causing local damage,” which happens if pressure on a diver reduces too rapidly.
The DAN cites “joint pain” and “numbness” as common symptoms. Lack of treatment can lead to permanent damage such as “bladder dysfunction,” “sexual dysfunction” and “muscular weakness.”
According to the DAN, exceeding or coming close to diving table limits too quickly is the most common cause of DCS.
“These days, people rely on computers, but they often forget to pay attention to the depth (dive computers indicate),” said Aaron Burrows of Destiny Charters. He said, “Staying within your decompression limit is important. There are also apps that are helpful.”
DCS is defined by DAN as one of the two kinds of Decompression Illness (DCI). The other type of DCI is arterial gas embolism (AGE). The DAN explains that AGE can happen if a diver ascends without exhaling air. The ascend makes air in the lungs expand, which can break lung tissue and send gas bubbles to the arterial circulation. This can lead to brain damage. The network’s website says the key to AGE prevention is to “always relax and breath normally during ascend.”
When swimming or diving off Okinawa, be cautious of rip currents. Because coral reef surrounds the island, locations where the currents occur are thought to be predictable. But, what if you get caught by one?
“You are not going to be able to swim against it. If you get caught by one, you are going to have to ride it out,” Joyce said. “Once it dissipates, you swim perpendicular to it to get out of it. Then you transition back to shore.”
Before you visit a dive site in Okinawa, get as much information about the currents as possible as this could better help you to avoid these dangerous conditions.
“Dangerous” marine life
Beyond the risk of open seas on the surface, there is also a long list of marine life that can pose potential danger to swimmers and divers. Box jelly fish, lion fish, moray eels and sea snakes may be enough to discourage some from testing the waters, but experienced dive instructors have a different view.
“The biggest problem with dangerous animals in the water, is typically caused by divers themselves – either inadvertently or on purpose,” Joyce said. “Most sea creatures will avoid competition. Fight or flight syndrome. Most of them are going to take off. If they come to you, they are basically there to check you out. If you just ignore it, it is going to be aware of (you) but ignore (you). It will go away.”
Several diving instructors refer to the “10-second rule” as a rule of thumb.
“Before you take anything out of the car, look at the water. If it takes longer than 10 seconds to decide, ‘Yes, this is a good time to dive,’ you should not dive that day,” a Tsunami Scuba instructor added.
Sometimes, being cautious may require listening to your gut and going against all the time and effort you put into making the trip out to the diving spot.
Equipment is also a vital component to ensuring safety. A Torii Scuba Locker employee advises rental gear is not always well-maintained. “We tell our customer to make sure that they check their gear as they were taught. If your gear is not good, that could get you killed.”
The employee also noted that social media is a very useful tool when it comes to getting information on diving safety.
“There are many communities of divers on social media. If you go on Facebook and type ‘Okinawa divers,’ it will give you many divers’ communities,” he said. “If you ask questions there, you will get many answers. Sometimes, you find someone (with good experience and skills) who is planning to go to a dive site that you want to go to.”
Monitoring sea conditions prior to and during a dive or swim is yet another component to keeping safe. Some locations offer live webcams to show the current conditions and there are also flags at some dive spots and beaches. At Maeda Point, blue means there are no problems, yellow means “OK to swim only with diving companies and instructors,” and red means “NO Swimming.”
On-base dive shops
Torii Beach Scuba Locker
Off-base dive shops
Address: 6-13-7 Mizugama, Kadena-cho, Okinawa
Address: 2288-243 Nakama, Onnason, Okinawa
*Naui Okinawa Dive Instructor
Tel: 090-9780-9543, Email: firstname.lastname@example.org
Divers Alert Network
Sea conditions by Shogun Weather
MCCS Dive site list
Hazardous marine life found in Okinawa