Experts: Divers on Okinawa should take care when temps dip
CAMP FOSTER, Okinawa — It’s that time of the year when the temperature plummets and Okinawans break out their winter coats.
That’s right — it’s 60 degrees.
OK, so no one is mushing their sled-dog teams through the streets of Naha.
However, the slight change in air temperature means the water is just cold enough to pose a threat to divers, surfers and other water-bugs who don’t take precautions against hypothermia.
Cold-water risk depends highly on the individual, experts say.
The 3mm or thinner wetsuit that many people use during warmer months probably isn’t enough during the winter, said Gary Haglund, staff instructor at Torii Beach Scuba Locker.
“A hooded vest and a 5mm wetsuit is good for most people,” Haglund said.
An off-the-shelf 5mm wetsuit costs about $150 and can be found at most local dive shops, Dunn said. Expect to pay more than $200 for a custom-made 5mm wetsuit, he said.
While a wetsuit traps a thin layer of water against your skin and restricts its movement, a drysuit keeps water out entirely.
However, most drysuits cost $800 and up. Divers who buy drysuits should get instruction on their use, said Ed Dunn, who publishes a weekly Okinawa dive report.
“If you don’t know what you’re doing, you could shoot to the surface and get ‘the bends’ or body squeeze,” he said.
The bends, or decompression sickness, occurs when nitrogen bubbles form in the body after a rapid ascent. The condition often goes away after causing discomfort, but it can sometimes be fatal.
If a drysuit is too much hassle and a 5mm wetsuit doesn’t provide enough protection, 7mm wetsuits are available via the Internet. They are less common on Okinawa, but they may be available at some local dive shops.
The water temperature usually drops as low as 68 degrees during January and February before rising again in March, Haglund said.
“If you dive over a period of several days, I found from personal experience that the body continually loses heat,” Haglund said.
Hypothermia begins when the body’s core temperature drops below 95 degrees, which will happen after prolonged, unprotected exposure to 68-degree water.
“It all starts with shivering,” Dunn said. “Get that person out of the water, then get them dried and warm.”
Drinking coffee or caffeinated beverages won’t ward off hypothermia prior to entering the water, Dunn said. However, hot drinks can help someone who is already hypothermic.
The warm-up process should be gradual, so avoid dunking a hypothermic person in a hot bathtub, Dunn said.
Getting in a car and turning on the heater is often effective, Haglund said.
As hypothermia progresses, a person’s skin may turn pale blue. The person can become disoriented and unable to answer simple questions correctly.
“Extreme cases like that need medical attention really fast,” Dunn said.
Do not let a hypothermic person go to sleep or the person may not wake up, he said.
Although there is less risk, boaters should also take precautions against the cold, Dunn said. Other experts advise bringing extra clothes should someone fall overboard.