The Kerama Islands guide: snorkeling, diving, and day trips
Where the Kerama Islands are
The Kerama Islands (Kerama-shotо in Japanese) are a national park and a small cluster of islands west of Naha, reachable by ferry or tour boat. Tokashiki and Zamami are the largest and most visited. Aka and Geruma are smaller. All are close to each other, separated by short boat rides. Most day-trip snorkeling and diving tours depart Naha (from a marina near Naha Port) and spend the day island-hopping among the same three to four snorkel sites, returning by late afternoon.
What makes Kerama Blue special
The water around the Keramas is extraordinarily clear. Locals call it "Kerama Blue"—a vivid turquoise that comes from shallow coral reefs, white sand, and minimal algae. Visibility is often 30 metres (100 feet) or more. Fish are abundant: parrotfish, grouper, angelfish, fusiliers. Sea turtles are common (green and hawksbill) and often glide past snorkelers at close range. It’s the reason the Keramas rank among Japan’s top snorkeling and diving destinations, and why a $49 day trip from Naha feels like a bargain.
Sea turtles and other marine life
Turtles are the showstopper. You won’t see them every dive or snorkel, but they’re common enough that guides report sightings on most trips. They’re usually curious and unbothered by slow, respectful snorkelers. The reef fish are brilliant and dense. Occasionally you see sea snakes (venomous but docile, not a threat if you don’t touch), eels, and nudibranchs. The guides brief you on do’s and don’ts; wearing the provided wetsuit helps protect against accidental brushes with stinging coral or sea urchins.
Snorkeling vs diving in the Keramas
Snorkeling: The Kerama Islands snorkeling day trip ($49) is perfect for beginners. Three snorkel stops over 5–6 hours. You can see fish and turtles in 5–15 metres of water without certification. Guides are in the water with you; bento lunch and tea are served on board. See the snorkeling guide.
Diving: The Kerama Islands intro-dive trip ($68) is a try-dive for first-timers (no certification needed). You descend to 10–12 metres with a guide (one-on-one or small group). The water clarity makes it ideal for a first dive; you see reef structure and fish clearly. Also snorkel option on the same day if you prefer. Operator is the same (Marine House SEASIR). See the diving guide.
Day trip vs staying over
Day trip (most common): Leave Naha 7–8 AM, return 3–4 PM. You get 4–5 hours in the water across multiple stops, food on board, minimal hassle. Suits most visitors. Costs $49 (snorkel) or $68 (dive).
Staying over: You can book accommodation on Tokashiki or Zamami and dive/snorkel multiple days or longer. Guesthouses and small hotels exist on both islands. Staying over gives you time to explore the island villages, eat local restaurants, and do back-to-back diving days. Less common for first-timers (adds cost and logistics), but ideal if you’re a keen diver or want to unplug from Naha.
Best season for Kerama visits
March to October is prime. Water is warmest (22–28°C / 72–82°F), visibility is high, and seas are calmest. June and July can be cloudy with algae, so May and September–October are considered the peak-clarity months. Winter (November–February) is still diveable and swimmable with a wetsuit, but casual snorkeling is less enjoyable (water ~20°C / 68°F). Typhoon season (July–September) can cause occasional cancellations or rescheduling; tours offer free rebooking.
First time in the Keramas? Book the snorkeling day trip ($49). You’ll see turtles, swim in impossibly clear water, and eat lunch on a boat. If you fall in love and want to dive or island-hop, book a return trip.
Book a Kerama Islands tour
See all Kerama snorkeling and diving tours on our snorkeling guide and diving guide. Both link to live dates and operator details.
Frequently asked questions
Where are the Kerama Islands?
West of Naha, a 50-minute boat ride. A small group: Tokashiki, Zamami, Aka, Geruma. A national park famous for gin-clear "Kerama Blue" water and sea turtles.
What can you do in the Kerama Islands?
Snorkeling ($49 day trip) or intro-diving ($68 day trip). Three snorkel stops per trip. Turtles, fish, Kerama Blue water. Also possible to stay over on the islands and dive multiple days, but day-trips are most common.
Can you see turtles in the Keramas?
Yes, commonly. Green and hawksbill sea turtles glide past snorkelers on most day-trip tours. Guides report turtle sightings regularly. You also see parrotfish, grouper, angelfish, and clear water (often 30m+ visibility).