Kerama Islands Snorkeling & Diving Guide 2026: Okinawa’s Marine Paradise

Thirty-five kilometers west of Naha, the Kerama Islands sit in a protected sea zone whose water is so extraordinarily clear and deeply blue that divers and snorkelers coined a specific term for it: Kerama Blue. The designation is unofficial but universal — anyone who has floated face-down over the coral gardens of Zamami or Aka Island understands immediately that the water here is something different in kind from coastal Japan, or indeed from most of the world. Visibility of 30–50 meters is the norm, not the exception. Sea turtles are so reliably present at Furuzamami Beach that local operators warn visitors not to chase them. From December through March, humpback whales breach in the protected waters between the islands. And beneath the surface, the Kerama Islands hold one of the most intact and biologically rich coral reef ecosystems in all of Japan.

This guide covers snorkeling and diving in the Kerama Islands in full: which islands to base yourself on, the best snorkeling and dive sites, how to book tours from Naha or from the islands themselves, what to expect at each site, and practical logistics for planning a trip. Whether you’re a first-time snorkeler or an experienced diver seeking new sites, the Kerama Islands deserve a place in any serious Japan travel itinerary.

What Are the Kerama Islands?

Geography and Overview

The Kerama Islands (Kerama-shotō) consist of approximately 20 islands, of which four are inhabited: Zamami, Aka, Geruma, and Tokashiki. The group was designated Kerama-shotō National Park in 2014, the 31st national park in Japan — recognition of both the marine and terrestrial ecological significance of the archipelago. Tokashiki Island is the largest at 19 square kilometers and the most commercially developed, with a ferry terminal, small town, two beaches (Tokashiku on the west, Aharen on the southwest), and a range of accommodation from guesthouses to small resort hotels. Zamami Island is smaller (6.7 square kilometers) but many divers and snorkelers consider it the better base for marine activities — the proximity of Furuzamami Beach to the village, the consistency of sea turtle sightings, and the quality of nearby dive sites make it the specialist’s choice. Aka Island (3 square kilometers), connected to Geruma Island by bridge, is the quietest and most remote of the three accessible islands, with pristine beaches and a permanent population of around 300. For more on the broader Okinawa archipelago, read our complete Okinawa outer islands guide.

Kerama Blue: Why the Water is Different

Kerama Blue is not a marketing invention — it has a specific cause. The Kerama archipelago sits on a narrow continental shelf that drops away sharply to deep oceanic water on its western side. This proximity to deep ocean drives strong tidal flows that constantly flush the inner island waters with clear, low-nutrient oceanic water, suppressing the algal blooms and runoff turbidity that degrade water quality in coastal environments. Combined with year-round water temperatures of 22–30°C that support coral growth, and the national park designation that limits fishing and development in the marine zone, the result is an ecosystem of exceptional clarity and biodiversity. The blue color comes partly from the depth and partly from the absence of the particulate matter and colored dissolved organic material that makes shallower coastal water greener or murkier.

Best Snorkeling and Diving Sites

Furuzamami Beach (Zamami Island) — Sea Turtles Guaranteed

Furuzamami Beach is a 10-minute walk from Zamami village and is the single most celebrated snorkeling spot in the Kerama Islands. The beach is modest (about 200 meters of white sand) but the snorkeling area — beginning just 20 meters from shore and extending over a shallow reef flat and then into slightly deeper coral garden — is extraordinary. Green sea turtles (Chelonia mydas) are present year-round, feeding on the seagrass beds in the shallower sections of the reef. On an average day, 5–10 turtles are visible without effort. They are habituated to snorkelers but protected by local rules: approach within 2 meters is prohibited, feeding is forbidden, and touching carries a significant fine under national park regulations. Coral diversity is high — multiple table coral formations, large brain corals, and healthy staghorn colonies — and fish life is abundant including parrotfish, wrasse, butterflyfish, and school of surgeonfish. The beach has a small facility building with rental equipment (mask, snorkel, fins: ¥500–1,000/set), changing rooms, and drinking water.

Nishi Beach (Aka Island) — Best Undiscovered Reef

Nishi Beach on Aka Island’s north coast is a short bike or scooter ride from the ferry terminal and sees perhaps a fifth of the visitors that Furuzamami receives. The coral reef immediately offshore is in exceptional condition — some dive operators describe it as among the least damaged in the entire Kerama group — with particularly impressive table coral formations at 3–5 meters depth accessible to snorkelers. Sea turtles are common here too. No beach facilities; bring your own equipment or rent from a dive shop in Aka village. The beach faces north, which means afternoon shade from the island’s ridge makes it less suitable for sun-bathing but keeps snorkelers more comfortable in summer.

Aharen Beach (Tokashiki Island) — Best All-Round Beach

Aharen Beach on Tokashiki’s southwest coast is the island’s main beach and offers an ideal combination of swimming, snorkeling, and beach facilities. The 800-meter beach has a gradual sandy entry, making it better for younger snorkelers or those not confident in the water than the steeper reef edges at some other sites. The outer reef section at the beach’s south end has good coral diversity and is accessible by swimming approximately 100 meters from shore. Boat rental (kayaks, SUP boards, small motorboats) is available from the beach shop; a motorboat takes you to nearby rock formations and coves with untouched coral in 10 minutes. Accommodation is available in the Aharen area with several minshuku and small resort hotels. Book via Booking.com for Kerama Islands accommodation.

Kerama Passage — Advanced Diving

The channel between Zamami and Aka islands is subject to strong tidal currents that create drift dive conditions — divers are carried along the reef wall by the current while marine life accumulates in the feeding-rich water. This site is for certified divers with drift experience. Visibility is typically 20–40 meters. Large pelagic species including Napoleon wrasse, grey reef sharks (occasional), and schools of jack and barracuda are encountered in the passage. Local Zamami dive operators run guided drift dives here; most require a minimum of Advanced Open Water certification or demonstrated drift experience.

Tropical Fish Kingdom — Shallow Coral Garden

This named snorkeling site off the east coast of Zamami Island (accessible by boat tour, approximately 10 minutes from the village) is a shallow coral garden of dense tropical fish diversity. Tens of thousands of fish — sergeant majors, chromis, damselfish — school above the coral in feeding aggregations that can envelop a snorkeler. The depth is 1–5 meters throughout, making it ideal for beginners and non-confident swimmers. Tour operators run scheduled snorkeling boat trips to Tropical Fish Kingdom 2–3 times daily from May through October; book through Kerama Islands snorkeling tours on Klook. For guidance on booking snorkeling tours across all of Okinawa, see our Okinawa snorkeling tour booking guide.

Humpback Whale Watching (December–March)

The Kerama Islands are one of Japan’s premier humpback whale watching destinations. Humpback whales (Megaptera novaeangliae) migrate to the Kerama area each winter to breed and give birth in the protected shallow waters between the islands. Sightings begin reliably from late December, peak in January and February (with reported encounter rates of 80–90% on whale watching boat tours), and taper off by mid-March. Behaviors observed include breaching, tail lobbing, and the extraordinary sound of male humpback song heard from boats stopped on the water. Dedicated whale watching tours depart from Zamami village (¥6,000–8,000/person for 2-hour tours, from approximately 7am and 2pm daily during season). Land-based viewing from Zamami’s hilltop observation point is also possible when whales are close to the island.

How to Book Kerama Islands Tours

Day Tours from Naha on Klook

The most convenient way to visit the Kerama Islands for a day trip is through an organized tour that includes ferry transport, equipment, and guided snorkeling. These tours typically depart Naha’s Tomarin Ferry Terminal at 8:30–9:00am, spend 4–5 hours in the Kerama Islands (usually at 2–3 snorkeling sites), and return to Naha by 5–6pm. Prices range from approximately ¥12,000–18,000 per person and include return ferry, wet suit rental, mask and fins, and a Japanese-speaking guide (some tours offer English). Book in advance: Kerama Islands day tours and snorkeling on Klook. Day tours make sense for short stays; if you have 2+ nights in the Kerama Islands, island-based operators offer more varied experiences at similar prices.

Staying Overnight and Booking Island-Based Operators

Staying on Zamami or Tokashiki Island unlocks the best Kerama experiences: sunrise snorkeling at Furuzamami before the day-trip crowds arrive, evening whale watching in season, and night diving in the crystal-clear water with bioluminescent plankton. Zamami has approximately 20 guesthouses and minshuku (many include 2 meals), several small dive shops, and a village atmosphere unchanged for decades. Tokashiki has more commercial accommodation and is more easily accessible (more frequent ferries). Search overnight accommodation options across both islands via Booking.com for Zamami and Kerama Islands. Book at least 1–2 months ahead for summer, and for December–February whale watching season which also books up early.

Getting to the Kerama Islands

Ferry services connect Naha (Tomarin Ferry Terminal) to Zamami and Aka islands, and to Tokashiki Island. The Zamami-bound high-speed ferry (Queen Zamami) takes 50–70 minutes and costs ¥3,140 one-way for adults. The car ferry (Ferry Zamami) takes 2 hours and costs ¥1,880 one-way. The Tokashiki ferry (Liner Tokashiki, high-speed, 35 minutes, ¥2,530) or car ferry (Marine Liner Tokashiki, 70 minutes, ¥1,690) departs from Tomarin. Ferries run approximately 2–3 times daily in each direction. Book through the Zamami Village Ferry website or at the ferry terminal; advance reservation is essential for July and August and for the whale watching season.

Tips for Visiting the Kerama Islands

Best Time to Visit for Snorkeling and Diving

Year-round conditions are suitable for some form of marine activity in the Kerama Islands. The optimal snorkeling and diving season is April through November, with peak conditions in May–June (water 24–26°C, visibility excellent, minimal crowds) and September–October (water still warm at 26–28°C, post-typhoon crowds thin dramatically). July and August offer the warmest water (28–30°C) but the most visitors — Furuzamami Beach can be crowded on weekends. Winter (December through March) is prime whale watching season; water temperature drops to 22–24°C and wet suits are recommended for snorkeling. The Kerama Islands are relatively sheltered from the northeast winter winds that affect the main island’s east coast, making winter visits more comfortable than on Okinawa itself.

Marine Park Rules and Coral Protection

The Kerama-shotō National Park has specific marine regulations that all visitors must follow. Do not touch or stand on coral — contact kills the coral polyps and recovery takes decades. Do not collect any marine organisms, shells, or coral fragments. Do not feed fish or sea turtles (feeding disrupts natural feeding behavior and can cause dependency). Maintain a 2-meter minimum distance from sea turtles. Some operators provide reef-safe sunscreen but it’s best to bring your own mineral-based (zinc oxide or titanium dioxide) SPF 50+ sunscreen. The regulations are enforced by national park rangers and local dive operators; violations are taken seriously.

What to Pack for a Kerama Islands Trip

Essential items include: reef-safe sunscreen (SPF 50+), UV-protective rashguard (more protection than sunscreen for extended water time), water shoes or reef walkers for entries over rocky reef edges, a dry bag for phone and valuables, and a reusable water bottle (vending machines are sparse on smaller islands). If bringing your own snorkeling mask, ensure it fits properly before arrival — a leaking mask ruins the experience. Anti-fog solution for mask lenses is highly recommended. For overnight stays, pack for a simple island lifestyle: few restaurants open late, shops have limited stock, and most guesthouses have no air conditioning (Okinawa breezes are usually sufficient).

Insider Tips for Sea Turtle Encounters

The best turtle encounter at Furuzamami Beach occurs in early morning (before 9am) when fewer snorkelers are in the water and the turtles are actively feeding in the shallower reef sections. Move slowly and horizontally — sudden vertical movements (diving down toward a turtle) cause them to retreat. Float at the surface and let the turtle come to you; curious individuals will sometimes approach and investigate stationary snorkelers. The turtles at Furuzamami are of the green turtle species (Chelonia mydas), vegetarian, and typically non-threatening. Loggerhead turtles are occasionally sighted in deeper water around the islands.

FAQ: Kerama Islands Snorkeling and Diving

Do I need to be a strong swimmer to snorkel at Furuzamami Beach?

Basic swimming ability is sufficient — the reef begins close to shore in calm water, and the snorkeling area is protected from strong currents by the reef structure. In rough conditions (typically during typhoon approach or strong northerly winds in winter), the beach is closed. A life jacket or snorkeling vest is available for rent and is recommended for non-swimmers or children. The water is warm year-round so cold water is not a concern.

Can I book a scuba diving certification course on Zamami Island?

Yes. Several dive operators on Zamami offer PADI Open Water Diver courses over 3–4 days (approximately ¥50,000–60,000 including course fees). Some operators offer English-language instruction with advance booking. The Kerama Islands are considered an excellent environment for certification: clear warm water, gentle currents in sheltered areas, and outstanding marine life that keeps students motivated. Contact Zamami dive shops directly or check Klook for available packages.

How far in advance should I book Kerama Islands whale watching tours?

December through February — the peak whale watching season — sees very high demand for both ferry tickets and overnight accommodation. Book ferry reservations and guesthouse stays 1–2 months in advance at minimum. January and February weekends book out within days of the reservation window opening. Whale watching boat tours can sometimes be booked on arrival, but dedicated whale watching packages that include overnight accommodation and guaranteed tour spots should be reserved much earlier.

Is the Kerama Islands visit suitable for families with young children?

Yes, with appropriate preparation. Aharen Beach on Tokashiki and some beaches on Zamami have gentle sandy entries suitable for young children. The sea turtles at Furuzamami are a particularly memorable experience for children 6 and older. Younger children should wear life vests, and a rashguard and reef-safe sunscreen are essential. Most guesthouses accommodate families, and the slower pace of island life is well-suited to children.

What is the difference between the Kerama Islands and the Miyako Islands for snorkeling?

Both offer excellent snorkeling, but they differ in character. The Kerama Islands are closer to Naha (35km vs 300km), easier to reach, and particularly famous for sea turtles and seasonal whale watching. The Miyako Islands have more extensive white-sand beaches, better conditions for beginners due to gentler reef entries, and the spectacular Aragusuku Beach on Kurima Island. Serious divers tend to prefer the Kerama for dive site variety and conditions; beach-goers often prefer Miyako. See our Miyako Islands travel guide for a full comparison.

Related Articles

• Complete Okinawa outer islands guide
• Miyako Islands travel guide
• How to book snorkeling tours in Okinawa
• Okinawa Ryukyu culture guide
• Okinawa main island travel guide

Conclusion

The Kerama Islands represent one of the most accessible world-class marine environments in the entire Asia-Pacific region — less than 90 minutes from central Naha by high-speed ferry, and with conditions that rival the Coral Triangle nations at a fraction of the logistical complexity. Three key takeaways: First, the sea turtle experience at Furuzamami Beach is genuinely extraordinary and widely accessible to beginner snorkelers. Second, overnight stays unlock the best Kerama experiences — early morning at Furuzamami before the day-trip crowd arrives is a fundamentally different, better experience than a midday visit. Third, December through March adds a whale watching dimension that has no parallel in accessible Japanese waters.

Start planning: browse Kerama Islands snorkeling and diving tours on Klook. Find accommodation across all three main islands via Booking.com for Kerama Islands. Kerama Blue is waiting.