reef
all-levelsboat entry

Aka Island - Nishi Hama

Naha · Kerama Islands, Okinawa · Japan

Nishi Hama, or Nishibama Beach, on Aka Island is one of the crown jewels of the Kerama Islands, a UNESCO-recognised archipelago lying roughly 40 kilometres west of Naha in Okinawa. The site is famous for what locals call Kerama Blue: a crystalline water clarity that can reach an astonishing 50 metres of visibility, making it among the clearest diving waters in all of Japan. The dive begins off the white sand beach that curves along Aka Island's western shore. A gentle sandy slope gives way to an expansive coral garden that stretches from the shallows down to around 25 metres. Over 200 species of reef-building corals have been documented in the Kerama Islands, and Nishi Hama showcases some of the healthiest formations in the chain. Table corals spread in broad canopies, staghorn thickets shelter clouds of damselfish, and massive Porites bommies stand as ancient sentinels on the reef. The diversity of coral structure creates a mosaic of habitats that support an equally rich community of reef fish. Sea turtles are the undisputed stars of Nishi Hama. Green turtles graze on seagrass beds in the shallows and rest under coral overhangs, while hawksbill turtles pick at sponges along the deeper reef wall. These gentle animals are remarkably tolerant of divers and frequently allow close, unhurried observation. Clownfish defend their anemone homes with comic ferocity, parrotfish crunch coral audibly, and the occasional whitetip reef shark glides past on the sandy bottom. The mild currents and moderate depth make Nishi Hama accessible to divers of all levels, from newly certified beginners to seasoned underwater photographers seeking the perfect turtle portrait in impossibly clear water. The site is equally spectacular for snorkelling, with corals and fish visible just metres from shore. Aka Island itself is a tranquil escape with a handful of dive shops, simple guesthouses, and an unhurried pace of life that stands in stark contrast to the main island of Okinawa. Daily ferries from Naha's Tomari Port connect in under an hour by high-speed vessel, making it a convenient day trip or overnight diving destination.

25 m
Max depth
30-50m
Visibility
March-November
Best season

Marine Life

green sea turtle
hawksbill turtle
clownfish
butterflyfish
parrotfish
whitetip reef shark
moray eel
sea snake
lionfish
giant trevally

Best Season to Dive

Highlighted months represent the ideal conditions for diving

21°C – 29°C
Jan
Feb
Mar
Apr
May
Jun
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Aug
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Oct
Nov
Dec

Location

Naha · Kerama Islands, Okinawa · Japan

Coordinates: 26.1920, 127.2870

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Dive Site Depth Profile

Visual depth progression and waypoint route for Aka Island - Nishi Hama

Max Depth:25m
Waypoints:5
0m0m5m5m10m10m15m15m20m20m25m25mSea SurfaceEntry2mReef section 115mDeepest point25mReef section 212mSafety stop5m
* Plot shows dive progression checkpoints sequentially from left to rightDiveOne Club Depth Profile v1.0

Why dive here

Legendary Kerama Blue visibility reaching 50 metres on the best days
Dense coral gardens with over 200 species of reef-building corals
Frequent green and hawksbill turtle encounters on the shallow reef

Videos

Kerama Islands Diving - Aka Island & Kuba Island, Okinawa, Japan

Conditions & safety

Skill levelall-levels
Entry typeboat
Max depth25 m
Currentmild
Visibility30-50m
Best seasonMarch-November
coral gardensea turtlekerama bluereefbeginner friendlyphotography

FAQ

What is Kerama Blue and why is Aka Island famous for it?

Kerama Blue is the term locals and divers use to describe the extraordinarily clear, vivid blue water found around the Kerama Islands. The visibility in these waters can reach up to 50 metres, far exceeding most tropical dive destinations. Aka Island sits at the heart of this phenomenon, where clean ocean currents sweep through the island chain and the healthy reef system keeps the water pristine. The clarity is so legendary that the term has become a marketing icon for Okinawa diving.

How do I get to Aka Island from Naha?

Aka Island is reached by ferry from Naha's Tomari Port. The high-speed Queen Zamami ferry takes about 50 minutes, while the regular Zamami ferry takes around 90 minutes with a stop at Aka. Ferries run daily but can sell out during peak summer months, so advance booking is recommended. Many dive operators on Aka can arrange accommodation packages including ferry transfers.

Is Nishi Hama suitable for snorkelling as well as diving?

Yes, Nishibama Beach is one of the best snorkelling spots in the Kerama Islands. The shallow reef starts just metres from the white sand beach, with coral and tropical fish visible from the surface in knee-deep water. Sea turtles frequently visit the shallows, making it possible to swim alongside them while snorkelling. For divers, the reef extends to 25 metres with richer coral formations and larger marine life at depth.

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