Frequently Asked Questions

July through September is peak season with the best ocean conditions. However, to avoid crowds and high prices, April-June and October-November are recommended. Water temperatures stay above 24°C (75°F) from April to November. Even in winter (December-March), water temperatures remain above 20°C (68°F), and diving is possible with a proper wetsuit.

The Blue Cave (Aono Doukutsu) is located at Cape Maeda in Onna Village, central Okinawa main island. It is about 1 hour by car from Naha Airport (50 minutes via expressway). The semi-submerged cave is famous for sunlight creating an ethereal blue glow on the water surface.

Sea turtles (green and hawksbill), clownfish (Nemo), manta rays, whale sharks (at specific sites), coral reefs, nudibranchs, and hundreds of species of tropical fish. In winter, humpback whales migrate to Okinawa waters for breeding.

Yes, most tours accept individual participants. Solo travelers are common, and you will be grouped with other participants. Many shops also offer photo services so you can capture your experience.

Many shops offer services in English. OnlineOkinawa clearly lists the languages each shop supports. Some shops also offer Chinese and Korean language services.

Snorkeling requires a life jacket, so non-swimmers are welcome. Introductory diving is also fine as the instructor accompanies you throughout. However, if you have an extreme fear of water, please consult with the shop in advance.

You should wait at least 18 hours after diving before flying (DAN recommendation). If you did multiple dives, wait 24 hours or more. There is a risk of decompression sickness. Never dive on the same day as your return flight.

Yes. Snorkeling is generally available from age 6, introductory diving from age 10. Some shops offer shallow-water programs for younger children or glass-bottom boat rides. Life jackets are mandatory for everyone.

Participants with heart disease, asthma, epilepsy, diabetes, or other conditions require a doctor's clearance certificate. If you check any items on the pre-dive medical questionnaire, you cannot participate without medical approval.

Registered operators maintain emergency response protocols. Standard procedures include contacting the Japan Coast Guard (dial 118), having AED equipment available, and confirmed routes to the nearest hospital. For diving accidents, contacting DAN Japan (045-228-3066) is also critical.

Maruyu-certified shops have passed rigorous inspection by the Okinawa Prefectural Public Safety Commission, confirming their safety protocols, qualified staff, equipment maintenance, and insurance coverage. While certification is a reliable indicator of safety standards, there are also excellent non-certified operators.

During peak season (July-August, Golden Week), book 1-2 months ahead. At other times, 1-2 weeks in advance is usually sufficient. Popular shops fill up quickly, so book as soon as your dates are confirmed.

Policies vary by shop, but typically: 50% for cancellations 3 days to 1 day before, 100% for same-day cancellations. Most shops waive cancellation fees when tours are cancelled due to typhoons or other natural disasters.

Same-day bookings are possible if there is availability. However, during peak season this is often difficult, and advance booking is recommended to secure your preferred plan and time slot.

Most shops accommodate date changes. Notify them as early as possible. During peak season, your preferred alternative date may not have availability.

Cash and credit cards (VISA, Mastercard) are standard. Some shops also accept electronic payments and QR code payments. Online card payment at booking is available at certain shops.

Swimsuit, towel, change of clothes, and sunscreen (reef-safe recommended) are the basics. For certified divers, bring your C-card. Contact lens wearers should ask about prescription mask availability.

Yes. Masks, fins, wetsuits, BCDs, regulators, and all other gear are available for rental. Most tour packages include equipment rental in the price. You are also welcome to bring your own gear.

It depends on the season. July-September is fine with just a rash guard, though some shops recommend wetsuits for jellyfish protection. From October onward, a 3-5mm wetsuit is needed. In winter (December-March), a 5mm full suit or drysuit is recommended.

Waterproof cameras and waterproof-cased smartphones are welcome. Many shops rent underwater cameras (around 1,000-3,000 yen) or offer guide photography services (free to about 2,000 yen). GoPro rentals are also available at some shops.

Soft contact lenses can be worn under the mask. However, disposable lenses are recommended since they may be lost if water enters the mask. Many shops offer prescription mask rentals as an alternative.

Yes, activities proceed in rain as long as ocean conditions are safe. Once underwater, rain does not matter. However, tours will be cancelled in the event of lightning or rough seas.

All marine activities are suspended when a typhoon approaches. Typically, cancellation decisions begin 2 days before the typhoon arrives, and seas remain rough for 1-2 days after it passes. Typhoon-related cancellations are almost always fee-free.

Yes, Okinawa offers year-round diving. Winter water temperatures are 20-22°C (68-72°F), and a 5mm wetsuit or drysuit keeps you comfortable. Winter actually brings the best visibility and is also whale watching season.

Okinawa's rainy season (tsuyu) typically runs from mid-May to late June. Despite the name, it rarely rains all day — there are often sunny periods. Marine activities operate normally when ocean conditions allow.

Coral spawning occurs around the full moon from late May to early June. It is observed during night dives. The exact timing is difficult to predict as it is a natural phenomenon, but divers gather around Kerama and Onna Village every year.

Introductory (discovery) dives typically cost 7,000-15,000 yen ($47-100 USD) per dive. Blue Cave introductory dives are around 8,000-12,000 yen. Kerama Islands day trips run 12,000-20,000 yen. Prices generally include guide fee, equipment rental, and insurance.

Beach snorkeling costs 3,000-6,000 yen ($20-40 USD), and boat snorkeling 5,000-10,000 yen ($34-67 USD). Blue Cave snorkeling typically ranges from 3,500-7,000 yen. Most packages include equipment rental and guide fees.

About 4,000-6,000 yen ($27-40 USD) per adult for a 2.5-3 hour tour. Children's rates are typically 50-70% of the adult price. Some operators offer a full refund guarantee if no whales are sighted.

Tipping is not customary in Japan and is not expected. If you received excellent service, leaving a positive online review is the best way to show appreciation.

Yes. July-August peak season prices are typically 20-50% higher than standard rates. Conversely, winter (December-February) off-season discounts of 10-30% are common. Some shops offer early booking discounts or online reservation discounts.