Cross the Irabu Ohashi Bridge from Miyako Island and you reach Irabu Island. Hidden beneath its waters is a cave that glows blue when the sunlight reaches it, known as the Blue Cave.
Also called the Sapphire Cave, this spot is defined by one thing above all: there is no way in from land, only from the sea. That is exactly why the sight of sunlight filtering through the water and washing the cave in blue remains a reward reserved for those who make the trip.
This guide covers what makes the Blue Cave special, how to get there, how to choose a tour, the best time of day to visit, and the points worth knowing before you go.
Blue Cave Ratings
Blue Cave Essentials
| Also known as | Sapphire Cave |
| Location | Irabu Island (Miyakojima City) |
| Admission | None (tour fees charged separately) |
| Best season | Spring to autumn (outside typhoon season) |
| Best time of day | Mornings, close to high tide |
| Lifeguard | None |
| Restrooms / showers | None |
| Official website | – |
The Blue Cave is not a beach in the usual sense. It can only be entered from the surface or from underwater, so there are no swimming facilities or lifeguards, and it is not somewhere you can simply drop by on your own.
On a guided tour, however, everything is set up so that even beginners can enjoy it safely, and you can visit by either snorkeling or diving.
What Makes the Blue Cave Special
Plenty of Tours Suitable for Beginners
Even if you are not a confident swimmer or have never snorkeled before, tours that require life jackets and include a guide are perfectly manageable.
There are also many introductory diving plans that require no certification, so if you want to look up at the blue light from underwater, that is the option to choose.
The “Sapphire Blue” Created by Sunlight
The highlight of the Blue Cave is the moment sunlight enters through the mouth of the cave, reflects through the water, and floods the interior with blue.
The intensity shifts with the angle of the light and the height of the tide, so the same cave looks completely different depending on when you visit. The nickname Sapphire Cave comes from this jewel-like blue.
A Place You Can Only Reach From the Sea
There is no land route to Miyako Island’s Blue Cave.
Your only options are to approach the entrance by boat, or to snorkel out from a nearby beach.
That very difficulty of access is also the reason the scenery inside has stayed unspoiled.
You Might Even Meet a Sea Turtle
The waters around the Blue Cave have well-developed coral and plenty of fish. Sea turtles are sometimes encountered on the way to the cave or inside it.
The seas off Irabu and Shimoji Islands are already known for high sea turtle sighting rates, and many tours combine the Blue Cave with sea turtle snorkeling.
The Best Timing Is “Morning Plus High Tide”
The blue depends heavily on how high the sun sits. Mornings, when the sun has climbed high, combined with a tide close to its peak, are considered the most beautiful.
In the afternoon the currents shift more readily and clarity tends to drop compared with the morning. When booking, look at morning departures first.
Going Alone Is Dangerous. Guided Tours Are the Norm
Visiting the Blue Cave independently is not prohibited, but the currents are strong and parts of the cave are dark and narrow, making it extremely risky to enter without knowing the terrain.
There are no lifeguards, so there is no one to call on if something goes wrong. Joining a guided tour run by a dive shop is strongly recommended.
Blue Cave Video
Here is a video of Miyako Island’s Blue Cave. Please take a look.
Access and Parking
| Access | About 30 minutes by car from Miyako Airport |
| Address | Irabu, Miyakojima City, Okinawa |
| Parking | Available |
| Restrooms | None |
There are two parking areas, one on the Sabautsugaa side and one on the Sabaoki Park side. Both are introduced below.
[Parking on the Sabautsugaa side]
[Parking on the Sabaoki Park side]
How to Choose a Blue Cave Tour
Snorkeling or Diving, Which Should You Pick?
Snorkeling means taking in the cave’s blue from the surface, which is easier on your stamina and more manageable if you have young children with you.
Introductory diving puts you below the surface looking up, and the blue reads completely differently. Most plans require no certification, making this the choice for anyone who wants to experience the cave more fully.
Typical Prices and Duration
| Half-day plan | About 2–3 hours / from around 6,900 yen |
| Full-day plan | About 5 hours / from around 12,000 yen |
| Time in the water | Roughly one hour |
Prices and durations vary by operator and season. Treat the figures above as a guide and confirm the latest details when booking.
Things to Check When Booking
Around the Blue Cave
All the Beaches of Irabu and Shimoji Islands
Irabu and Shimoji Islands are home to plenty of beautiful beaches.
If you want to cover the whole area efficiently, take a look at this guide as well.
Activities on Miyako Island
Snorkeling, diving, SUP, and other marine sports in Miyako Island’s crystal-clear water are hugely popular.
Blue Cave tours can be booked here as well. Popular plans fill up early, so reserve as soon as your dates are set.
Rental Cars on Miyako Island
A rental car is by far the best way to get around Miyako Island.
With a car you can cross the Irabu Ohashi Bridge and reach Irabu Island, where Blue Cave tours meet, with ease. Bus services on Miyako Island are infrequent, and having a car makes a huge difference to how much you can fit in.
Reservations fill up quickly in peak season, so book early once your travel dates are decided.
Frequently Asked Questions About the Blue Cave
Can I join if I cannot swim?
Many plans welcome weaker swimmers, provided the tour requires life jackets and includes a guide.
If you have any concerns, raise them when you book.
Can I bring children?
Minimum ages vary by operator.
Most plans start from elementary school age, so check in advance whether preschool-age children are permitted.
Which months are best?
Spring through autumn is ideal, when the water is clearest and the weather most settled.
Summer is prone to typhoons, however, so checking the forecast and sea conditions is essential.
Do tours get cancelled?
Yes. The Blue Cave is heavily affected by sea conditions, and tours are called off on days with high waves.
Scheduling it early in your trip leaves room for a backup day if it is cancelled.
Summary
Miyako Island’s Blue Cave, the Sapphire Cave, sits beneath the waters off Irabu Island and cannot be reached from land. The sapphire glow created by sunlight is a sight reserved for those who actually make the journey.
Two things are worth keeping in mind: aim for a morning close to high tide, and go with a guided tour. Sea conditions can force a cancellation, so leave some slack in your itinerary.
Nakanoshima Beach, Toguchi no Hama, and Sawada no Hama are all nearby. Combine them and you have a full day exploring the waters of Irabu and Shimoji Islands.
Thank you for reading to the end.
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