What is the best time to dive Yonaguni?

The best months to dive Yonaguni in Japan are December, January, February, March, April, May. Water temperatures range from 21°C to 29°C during peak season.

How deep is Yonaguni?

Yonaguni reaches a maximum depth of 40 m, with visibility ranging from 15–49 m. The full depth range requires Advanced certification at minimum; some zones are technical diver territory.

What marine life can you see at Yonaguni?

Yonaguni is known for encounters with manta ray, whale shark, reef shark, sea turtle, seahorse, nudibranch. The site features reef, pelagic diving across 5 named sites, with a marine life score of 80/100 in OkToDive's ranking.

Is Yonaguni good for beginners?

Yonaguni is better suited to experienced divers. Currents can be moderate and depths reach 40 m. A minimum Open Water certification is required, and OkToDive recommends at least 100 logged dives before visiting.

How much does it cost to dive Yonaguni?

A 2-tank dive at Yonaguni averages around $100 USD, placing it in the mid range tier. Both boat and shore access are available, giving divers flexibility on budget.

Yonaguni Diving — Japan's Mysterious Underwater Ruins

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World Class

Intermediate

Yonaguni

JapanAsia-Pacific

66.7

SCORE

24.4500°N

122.9500°E

Yonaguni is Japan's westernmost island, famous for two things: schools of 100+ hammerhead sharks from November to March, and the mysterious underwater 'monument' — terraced stone structures at 25m that may be natural or man-made. The hammerhead season coincides with excellent 30m+ visibility and dramatic underwater scenery.

Japan's Mysterious Underwater Monument

Visibility15–49 m

Temperature21–29°C

Max Depth40 m

Currentmoderate

2-Tank Dive$100

Best MonthsDecember, January, February, March

CertificationOpen WaterIntermediate

Score breakdown

Click any score to see a detailed breakdown

Marine Life

80.0

Species diversity, megafauna encounters, reef fish abundance, macro life, and endemic species.

Species Diversity

100

Megafauna Encounters

Reef Fish Abundance

100

Macro Life

Endemic Species

Marine life diversity

80.0

Coral & reef health

72.0

Visibility & conditions

80.0

Dive site variety

39.0

Water temperature

59.0

Depth & access

62.0

Operator quality

78.0

Topside experience

64.0

Getting there

68.0

Value & cost

54.0

Crowding

57.0

Social proof

57.0

Key species

manta ray whale shark reef shark sea turtle seahorse nudibranch cuttlefish whale

Dive types

reefpelagic

Traveling with non-divers?

Your non-diving travel companions will find plenty to enjoy topside while you're underwater. Here are some activities to consider.

Activities for non-divers

Yonaguni horse ridingDr. Ishi monument (westernmost point of Japan)Tindahanata cliff viewpointlocal awamori distillery tour

Nearby cultural sites

Yonaguni Submarine Ruins (viewed from glass-bottom boat)
Kubura Bari rock formations

Non-diver score

4/10

Limited topside — plan ahead for non-diving partners.

Family FriendlyYes

Restaurants & Nightlifebasic

Safety & emergency

Dive insurance

DAN recommends dive insurance for all divers.

Learn more at DAN.org

Hyperbaric Chamber120 km — University of the Ryukyus Hospital Chamber, Naha

Nearest Hospital3 km

Small clinic on island; flight to Naha (1.5 hrs) for chamber; helicopter available

Skill LevelIntermediate

Current Strengthmoderate

Top operators

Yonaguni Diving Service

PADI

4.7

120 reviewsNITROX

Sou Wes Dive

PADI

4.6

90 reviewsNITROX

Compare this dive site

Yonaguni in Japan scores 66.7/100in OkToDive's 12-category data-driven rating. Best for reef diving with 15–49m visibility and 21–29°C water temps. A 2-tank dive costs ~$100 USD. Peak season: December, January, February.

Last updated: 2026-05-24

Who should dive here

Best for

+ Divers who prioritize reef diving
+ Anyone visiting Asia-Pacific for the first time
+ Groups seeking 5+ named dive sites in one area

Skip if

− You don't have Advanced certification
− You need shore access — this is boat-only

Verdict

Choose Yonaguni over similar Asia-Pacific destinations when marine life matters more than site variety

How Yonaguni compares

Site	Score	Visibility	Cost/dive	Best for
Yonaguni	66.7	15–49m	$100	reef, pelagic
Raja Ampat	81.4	15–30m	$180	reef, wall
Sipadan Island	81.3	18–40m	$120	wall, reef
Komodo National Park	78.4	9–30m	$100	drift, reef
Tubbataha Reef	76.0	24–46m	$200	wall, reef

Current conditions

9/10Excellent

Waves1.54 m

Swell1.4 m

Wind14.1 km/h

Air25.9°C

Mainly clear

43d ago

Honest reality check

What your dive shop won't tell you

The minimum certification printed on a brochure is the legal floor, not the honest recommendation. Here's what we actually think you should bring to this site.

Recommended logged dives

40+

Below this we'd send you somewhere easier first.

Recommended certification

Advanced Open Water

“Intermediate minimum — deep profiles and variable viz.”

What will challenge you

→Moderate currents. Expect to drift — this is not a skill-builder site for a first trip after certification.
→Recreational limit of 40 m is reachable here (max depth 40 m). Gas planning and NDL tracking matter.
→Cooler than most tropical sites — 21°C minimum. A 5 mm wetsuit is the floor for longer dives.

What will surprise you

→Thermoclines can drop water temp by 8°C between the surface and depth. Your wetsuit choice should match the minimum, not the average.

Time of day

When to dive it

Every dive shop gives you this briefing at 7am. We just wrote it down. Tidal dependency: slight. Optimal window: First light to 11am for best visibility..

Morning

Viz
peak
Current
moderate
Crowd
light

reef exploration
photography

Best light and calmest conditions before afternoon wind picks up.

Afternoon

Viz
moderate
Current
moderate
Crowd
moderate

drift diving
second tank

Wind chop can reduce viz. Still diveable but morning is better.

Month-by-month

Dive forecast

Realistic conditions by month. Viz ranges are what you should actually expect, not best-case marketing numbers. Confidence % is the share of days that match this profile historically.

Month	Viz (m)	Temp (°C)	Current	Sea	Rain	Confidence	Highlights
Jan	32–49	25	Mod	Calm	Light	70%	reef fish active, peak season crowds
Feb	32–49	25	Mod	Calm	Light	70%	reef fish active, peak season crowds
Mar	32–49	25	Mod	Calm	Light	70%	reef fish active, peak season crowds
Apr	32–49	25	Mod	Calm	Light	70%	reef fish active
May	32–49	25	Mod	Calm	Light	70%	reef fish active
Jun	15–32	27	Mod	Mod	Wet	70%	reef fish active
Jul	15–32	27	Mod	Mod	Wet	70%	reef fish active, manta season
Aug	15–32	27	Mod	Mod	Wet	70%	reef fish active, manta season
Sep	15–32	27	Mod	Mod	Wet	70%	reef fish active, manta season
Oct	15–32	27	Mod	Mod	Wet	70%	reef fish active
Nov	32–49	25	Mod	Calm	Light	70%	reef fish active
Dec	32–49	25	Mod	Calm	Light	70%	reef fish active

Shoot here

Photography brief

Subjects are only half the shot. A perfect macro site is useless in a three-knot drift, and a wide-angle dream is useless at 35 m with a murky ceiling. These are the conditions, not the hype.

Macro subjects66

Wide angle67

Viz stability23

Hover friendliness70

Natural light56

Recommended kit

→General reef kit — mid-range wide or a 60mm macro depending on the specific site

Level up here

What this site will teach you

The dives that made you a better diver are the ones that made you uncomfortable for the right reasons. Here's what this site will quietly train you for.

Deep diving comfort
advanced
Regular dives past 30m build confidence at depth.

What it costsEstimates — calibration pending

7-day trip, per person

Rough ranges anchored to existing regional data — not booking quotes. Land-based trip, standard breakdown.

Budget

$2,200–$3,050

Hostels, shore diving, cheap eats

Flights (RT from US): $1,100–$1,300
Accommodation / day: $50–$100
Diving / day: $90–$100
Food / day: $10–$25
Transfers + misc: $50–$150

Mid-range

$3,350–$4,850

3-star hotels, standard boat ops, mix of restaurants

Flights (RT from US): $1,550–$1,850
Accommodation / day: $120–$220
Diving / day: $100–$130
Food / day: $30–$60
Transfers + misc: $50–$150

Splurge

$5,500–$8,550

Top resorts or liveaboards, premium operators

Flights (RT from US): $2,250–$2,750
Accommodation / day: $260–$500
Diving / day: $130–$170
Food / day: $70–$140
Transfers + misc: $50–$150

Budget decision guide

Choose Budget if you prioritize dive count over comfort — hostels and shore diving maximize bottom time per dollar. Choose Mid-range for the best balance of comfort and value — most divers land here. Choose Splurge for premium operators, private guides, and top-tier accommodation — worth it for special trips or non-diving partners.

Flights priced round-trip from a major US hub. Figures are per person on a shared room. Solo travelers add ~30% to accommodation.

Pair with

Build a trip around it

Most divers fly across the world for one destination and don't realise another worth-it site is 90 minutes away. Here are the honest pairings.

Best dive types here

Yonaguni Diving — Japan

Score breakdown

Marine Life

Key species

Dive types

Traveling with non-divers?

Activities for non-divers

Nearby cultural sites

Non-diver score

Safety & emergency

Dive insurance

Top operators

Yonaguni Diving Service

Sou Wes Dive

Who should dive here

Best for

Skip if

Verdict

How Yonaguni compares

What your dive shop won't tell you

When to dive it

Dive forecast

Photography brief

What this site will teach you

Deep diving comfort

7-day trip, per person

Budget decision guide

Build a trip around it