Water Safety updates

Updated on 7th June

 Characteristics of Okinawa climate and wind

  1. Climate Overview:
    • Okinawa experiences a sub-tropical climate with mild winters and long, muggy, and rainy summers.
    • The main island of Okinawa, along with smaller islands like Kerama, Miyako, Ishigaki etc, share similar weather patterns.
    • During summer (June to August), the region sees significant changes.
  2. Weather Patterns:
    • Rainy Season: The rainy season, known as “Baiu” starts in May and continues into June. During this period, frequent rains and cloudy skies are common.
    • Sunshine Hours: Sunshine is relatively scarce during the rainy season. However, after the rainy season ends in late June, sunny days become more frequent.
    • Ultraviolet Rays: Okinawa experiences the strongest ultraviolet rays of the year during summer. Proper skin and eye protection are essential.
  3. Temperature and Humidity:
    • Maximum Temperatures: While Okinawa is hot, maximum temperatures rarely exceed 35°C (95°F).
    • Humidity: High humidity levels contribute to the muggy feel during summer.
  4. Typhoons:
    • Typhoon Season: Typhoons tend to approach Okinawa during summer. It’s essential to stay informed about weather updates and take necessary precautions.
    • Obon Holiday: August, when typhoons are more likely, coincides with the Obon holiday, leading to increased travel.
  5. Marine Activities:
    • Summer is an excellent time for marine activities on the west coast of Okinawa. Clear waters and warm temperatures attract visitors for snorkeling, diving, and beach outings.

Remember to protect yourself from accident, from the intense sun, and enjoy the beautiful marine environment! 

Updated on 31st May 2024

Introducing safety handbook for river activity

Useful tips are included in the safety handbook below. (Japanese only)

Safety Handbook for river activity from Japan River Foundation 

Updated on 24th May 2024

 Safety Guidelines for Wearing a Life Jacket in River Activity

The water may appear shallow at first glance but can be steep and deep.

Moss, wet stones, and concrete, such as seawalls and shallow rocks at the water's edge, can be slippery. The water's edge is an area where there is a danger of falling into such water or being pulled in, as well as an area where the boundary between land and water can quickly change due to rising water, such as rainfall upstream.

Therefore, if there is a possibility of entering the land side of the water about 3 to 5 meters from the water's edge, wearing a life jacket can significantly reduce the risk of falling into the water.

(This depends on the condition of the river, the presence or absence of fences, the ease of approach to the water's edge, and footholds from which it is easy to fall over.)

Gudeline HP

ライフジャケット着用の目安 河川での活動 


Updated on 17th May 2024

 Safety Tip Use of Diver down flag for Snorkeling and Diving

When snorkeling or diving, it is highly recommended to display the diver down flags. These flags serve an essential purpose, especially in areas like Onna Village and throughout Okinawa.

Why Display Diver Down Flags?  Many small boats operate near beaches and dive sites, often close to divers and snorkelers. By displaying the diver down flag, you signal your presence to boat operator. This helps prevent collisions with vessels and ensures smooth cooperation with local community.

The diver down flags is for your safety!

For marine recreation-related products including diver down flags and buoys are available at the Maea Ginowan.

Marea Ginowan branch  Ginowan city Dive shop site

MIC21 Naha city, Shop site

SeaSir   Naha city  Shop site

Stay safe and enjoy your water activities!


シュノーケリング、ダイビングをする場合、Diver down flagがついたブイを携行することを強くお勧めします。


Diver down flagを掲げての活動は船オペレータに対して自分の存在を示すための重要なツールになります。船との接触を避けるため、また地域と協力し安全で円滑な活動のため、Diver down flagを是非ご利用ください。

Diver down flagはあなたの安全のためにあります!

Diver down flag, buoyなどを含めマリンレジャー関連商品を買うことが出来ます。

マレア沖縄宜野湾店 (宜野湾マリン支援センター内)宜野湾市 Dive shop site

MIC21  那覇市 Shop site

シーサー 那覇市 Shop site



Updated on 10th May 2024

Hab jellyfish outbreak advisory

The waters around Okinawa Prefecture are home to the habu jellyfish, a highly venomous species. During beach season, there is an increase in the number of sting victims. In 2023, there were 66 incidents of people being stung or bitten by dangerous sea creatures. Out of these cases, 11 (approximately 17%) were caused by habu jellyfish. To address this, Okinawa Prefecture will issue a Habu Jellyfish Outbreak Advisory from June to September. Residents and tourists are urged to take precautions to avoid habu jellyfish stings. Recommendations include minimizing exposed skin while swimming, staying within jellyfish netting safe zones at the beach, and carrying vinegar for first aid in case of stings. 



ハブクラゲ注意報発令 沖縄県

Hab jellyfish outbreak advisory Okinawa prefecture English

Hab jellyfish outbreak advisroy Okinawa prefecture Chinese

Updated on 3rd May 2024

Registered Beaches in Okinawa

The Okinawa Prefectural Police has released a list of beaches under the Water Safety Ordinance.  This registration ensures that each location adheres to safety regulations, including designated swimming areas and the provision of qualified lifeguards to ensure the well-being of all beachgoers.

For detail information on each registered beach, including their location, please refer to the attached document.

Updated on 26th April 2024

 Useful website for water safety

In Japan, the official start of beach season is marked by the Umi-biraki ceremony. This signifies the opening of beaches and typically occurs from July onwards.

Before this ceremony, beach organizers prepare by cleaning, stocking beach houses, setting up nets to keep sharks and jellyfish away from swimming areas, and testing the water for safety.

The exact date of Umi-biraki varies across Japan. It begins in southern areas like Okinawa as early April, gradually moving northward to reach Hokkaido by Augus.

Before heading out the beach, it is essential to verify the site’s conditions to ensure a safe and enjoyable experience.

Please check this site. When you click on a specific location, it expands to display details about wave height, wind conditions and tide schedule for the day at the spot. Please see attachment as example.

Okinawa Marine Safety, created by Okinawa Prefectural Government

おきなわマリンセーフティ | ポータル | 海を安全に (marinesafety.okinawa)


Updated on 6th Oct 2023

October is a dangerous month to be out in the water. Find out why

Marine Corps Installations Pacific


Updated on 29th September 2023

Technology introduction: Japan Life Saving Association deployed AI camera system for water safety

To prevent water accidents caused by the rip currents, the Japan Life Saving Association deployed the seaside MIMAMORI(watch over) system that automatically detects the currents by analyzing images from webcams installed on the beach in real time and notifying swimmers' smartphones. For prompt lifesaving, if the current catches a person, a rescue request is sent to the lifesaver's smartwatch. The system will also notify swimmers' smartphones of the occurrence of offshore wind to alert them. (Research and development cooperation; Chuo University)

This system is deployed at four locations in mainland, corporate with local government.


Japan Life Saving Association (Japanese)

Two YouTubes in the page showing;

  1. AI system detects the rip current.
  2. Example of AI detection of the rip current and rescue by lifesavers.

AI detects the occurrence of rip currents (yellow frame), detects swimmers caught in the current area (red frame), and alerts lifesavers' smartwatches with a rescue request to enable prompt rescue.


Other information in this website. (English page)

Rip Currents

What if a hits Tsunami?


Updated on 22nd September 2023

Okinawa marine leisure service provide list updated

The Okinawa Prefectural Police Headquarters has released a list of service providers that meet police safety requirements under the Water Safety Ordinance as of September 22, for your reference. (Japanese only)

  1. Beaches (6)
  2. Pleasure boat operator (37)
  3. Diving services (30)
  4. Snorkeling serivces (19)


Updated on 15th September 2023

Water Accident Statistics in Okinawa prefecture during August

Okinawa prefectural police headquarter released a tentative statistic for water accident statistics for August. More accident occurred compared Y2022.

https://www.police.pref.okinawa.jp/docs/2015022200039/(Japanese only)


  • Safety messages from the police
  1. Be very aware that water is dangerous!
  2. Do not underestimate the power of nature!
  3. Do not overestimate your own physical strength, knowledge and skills
  4. Wear life jackets and other buoyant equipment
  5. Use snorkels properly
  6. Do not go alone, stay with group
  7. Promote water accident prevention to the elderly and children


Memo from OHS

  • You can learn about water safety and risk mitigation at sea in the following resource.

Water Safety (OIST e-front)

Water Safety (US Marine Corp)

Okinawa Marine Safety (Okinawa Prefectural Police)


Updated on 8th September 2023

11th Regional Coast Guard Headquarter released water related accident statistics

According to the Okinawa times, https://www.okinawatimes.co.jp/articles/-/1207973 (Japanese only), the number of water-related accidents in Okinawa Prefecture involving middle-aged and older adults aged 50 and over is increasing. According to the Coast Guard Headquarters, the number of people over the age of 50 who have been involved in water accidents in Okinawa Prefecture this year is 106 (preliminary figures) as of August 17, with 53, or half of the total, being over 50 years old. The officials in charge of the 11 districts are urging people to take care of their physical condition and enjoy their leisure time in the sea.

Of the 40 fatalities or missing, 80%, or 30 people, were 50 years old or older.

Among water accidents, snorkeling accidents accounted for the most significant number of marine leisure accidents (17), while 12, or 70%, were 50 years old or older. 

This year, the five snorkeling fatalities were not limited to middle-aged and older adults, and none were wearing life jackets.

(From OHS)

Tips for water safety:

  1. Avoid going alone, stay with groups. That way there will be more potential help available and a higher opportunity of prompt response in the event of an emergency.
  2. Obtain information on the day’s weather and sea condition.
  3. Postpone activities if unfavorable weather is predicted.
  4. Let someone know, such as your family or friends where you are going, what activity is planned, with whom and what time you expect to return. So that emergency response organization will be able to respond in early stage in case of emergency.
  5. Do not allow your children to swim alone. Accompany them all times and watch over them until they are out of the water.
  6. Securing the buoyancy by wearing life jacket or wetsuits
  7. Take necessary training from professional when using equipment such as underwater mask, snorkel, fins, paddle boat, SUP etc, to make sure your skills are adequate for the condition.


Updated on 1st September 2023

Okinawa prefecture has extended the period of the box jellyfish advisory to 30 September 2023

Reports of injuries from encounters with box jellyfish are on the rise this year and these creatures seem to be in abundance along Okinawa beaches.

Please visit the links for details and, the advisories include prevention measures and first aid.

【Announcement from Okinawa Prefecture】






Updated on 25th August 2023

Marine safety product introduction: Personal Locater Beacon (PLB)

PLB introduction by Ministry of Internal Affairs and Communications

A PLB is a device that notifies the Japan Coast Guard via satellite when an individual fall overboard or drifts away from a vessel, etc. and reports the distress to the Coast Guard. The PLB can be used only in the case of maritime distress when the PLB is licensed as an automatic distress reporting station.

Product site

Updated on 18th August 2023

Okinawa prefectural police release warning message about Stung by Habu Kurage (Box Jellyfish)


-What happened?

On August 11, two incidents of swimmers were stung by Habu Kurage on beaches in the northern part of the main island. Both were children, and one of them became unconscious after being stung, and recovered by doctor’s treatment who attended there coincidentally, then transferred to the hospital by ambulance.

-First aid

Remove the tentacles by pouring vinegar on the affected area, cool it with ice, etc., and then take to a medical institution.

Be sure to include vinegar in your beach safety kit which and be used to remove jellyfish tentacles.

-How to avoid?

Stings can be avoided by wearing reef shoes and long-sleeved rash guards and scanning the area carefully before jumping into the water.

Stay safe, and look/think before you swim.


Updated on 4th August 2023

Websites relating water safety

  • Created by US Marines Camp Butler Base Safety Office

Water Safety

*Topics example:  Snorkeling safety videoOcean safety video, and more

*External website links for weather and sea condition

  • Created by Okinawa Prefectural Police

Okinawa Marine Safety Portal (Japanese only)

*Topic example: How to enjoy sea of Okinawa safely

Hazard map

*External website links for Windy, Weather forecast, Recommended marine business entities, and more


Updated on 21st July 2023

Typhoon #5 is approaching!

Typhoon #5 (called Tokusuri) has formed and is moving toward the Okinawa region while developing.

Category forecast when it is near Okinawa region: Very strong


Maximum wind


33m/sec, 64knots~44m/sec, 85knots

Very strong

44m/sec, 85knots~54m/sec, 105knots


54m/sec, 105knots~

 Link Japan weather association jp tenki

 Windy. com

  • Anticipated situation:

Streams and ditches swollen by rain make it difficult to see boundaries, causing accidents such as falls. Landslides and landslides are also more likely to occur. Even in places that are usually considered safe, be on your guard and avoid dangerous places unnecessarily.

When a typhoon approaches and becomes a storm, there is a risk of objects being blown away by the wind, being hit by flying objects, or having your car overturned. Also, hands and fingers can get caught in doors and fences.

  • Tips for action:

Avoid going out unnecessarily and wait until the typhoon has passed. Waves near the coast often become high before the typhoon approaches, and the sea level is high for some time while the typhoon passes. When a typhoon is coming, do not go out to see high waves at sea or near the coast. Stay home, stay safe!


Updated on 14th July 2023

Diving safety for drift diving, lesson learnt from the incident at Itoman July 19, 2023

What is Drift diving?

 Divers enter the water from a boat and move through the water with the current.

The boat follows the diver by following the SMB(Surface Marker Buoy)towed by the diver, by tracking the exhaust bubbles and predicting where the diver will surface and meet up with the diver.


Weather: Cloudy, wind 10 meters south-southwest, wave height 2 meters

The number of divers: 5 guest divers and two instructors.

Time order

  • 11:50:   600 meters northeast of Lukang Reef: Boat captain found no diver beneath the SMB, then called 118 (Coast Guard). Coast Guard and police helicopter began search and rescue operation.
  • 13:55   Found 6 persons with no injuries at 4 km southeast of Lukang Reef,
  • 14:45   Found one person (who chased the boat) with no injury at 1 km southeast of Lukang Reef,

Lesson learnt from this incident

  1. All the members understand overall schedule and procedure on in case of trouble. Check with the guide/instructor and boat captain. Example: weather/sea condition, time schedule, dive plan (team formation, dive path, maximum depth, dive time, residual pressure)
  2. Know that boat and divers may be drifted in different direction.
  3. Guide is to dive according to the dive plan
  4. Boat captain keeps eye on not only the diver position, but also be aware of other boat traffic around them, and time management.
  5. To provide communication device with boat captain, such as

a)  Whistle, dive buzzer 【audio device】

b)  SMB, light, signal mirror 【visual device】

c)  GPS, PLB(Personal Locator Beacon)【radio device】



Information source



Updated on 7th July 2023

Safe and secure life on leisure in sea and river

The Okinawa prefectural police are taking various measures to prevent water accidents so that many people can enjoy leisure activities in the sea and rivers while coexisting with water. 

Remember that water accidents are not someone else's problem but that everyone involved in water can become a party at any time.




# Victims


# Fatal

2020 (Jan-Dec)





2023 (Jan-May)






To prevent drowning accidents

  • Be aware that water is dangerous

Humans are constantly breathing to live. Even if they cannot move or faint, they can still survive in an environment where they can breathe, but not in water. Always be aware that one wrong decision may lead to death, and try to mitigate the risk. 

  • Please don't underestimate the power of nature  

Humans, no matter how good they are at swimming, cannot win against the forces of nature. ( Example: cannot swim against the rip current)

Okinawa Island faces the open ocean and is directly affected by tidal currents, waves, and wind.

When a typhoon is approaching or the weather is unfavorable for the activity, never go near the coast. There have been cases of people coming to the shore out of curiosity, with disastrous consequences.

  • Do not overestimate your own physical strength, knowledge, and skills

Swimming or floating in water is a tough exercise that consumes your physical strength. Always consider your age, physical strength, and the time you can spend in the water area, and never enter the sea if you consume alcohol or are feeling unwell.

Also, don't let your guard down just because you have experience of leisure activities on the sea or river. Collecting information in advance about the presence or absence of dangerous spots and precautions is essential.

  • Wear a buoyancy device such as a life jacket

When snorkeling, fishing, SUP, canoeing, clam digging, etc., be sure to wear a life jacket or a buoyant wet suit.

Buoyancy floats the body on the surface, making it easier to secure breathing, and it also helps preserve physical strength in the event of a water accident.

  • Use your snorkel correctly

Snorkeling is one of the marine leisure activities that you can easily access. Still, there have been many water accidents involving local residents and tourists, such as ingesting seawater due to improper use of snorkels.

When snorkeling, wear the following 4-piece set and enjoy snorkeling like floating. ① Mask, ② snorkel, ③ Fins, ④ Life jacket: Taking proper training before going to the sea is highly recommended.

  • No solo participant 

Leisure on the sea or river alone carries the risk of a serious water accident. To safely enjoy marine leisure, please have company and never lose sight of another person. It also leads to arranging prompt rescue calls in the event of a water accident.

  • Encourage older people and children to prevent accidents 

People aged 50 and over account for 60% of the deaths caused by water accidents in Okinawa, and the fatality rate of water accidents increases proportionally with age.

Encourage older people who go out to catch fish or shellfish to wear life jackets and refrain from water activity when feeling unwell.

Also, do not allow children to swim alone; even if a guardian accompanies them, watch over the children until they get out of the water.

Shop selection for the marine activities

Okinawa Prefecture Ordinance Concerning Prevention of Water Accidents and Ensuring the Safety of Swimmers (Abbreviation: Water Safety Ordinance)

 Okinawa Prefecture has enacted the Water Safety Ordinance to prevent water accidents to protect sea users' lives, bodies, and property.

  • Notification is required to engage in the marine leisure business

In Okinawa prefecture, some industries require notice the Public Safety Commission when operating a business related to marine leisure. (Shop operating without the notice is subject to penalties.)

If you use a marine leisure shop, please confirm that they notified the Public Safety Commission, and please provide the commission information if you found the non-notified shop.

〈Links to police website: industries that notified: Japanese language〉

Memo from OHS

  • You can learn about water safety and risk mitigation at sea in the following resource: Water safety