L字アーチ
Dive site · Japan
Experienced divers only
Is it worth the trip?
78Good out of 100 for your dates
2 days tie for best
Mon 2 · 81 out of 100
- Sea
- 0.4 m
- Wind
- 6 kn
- Gusts
- 9kn
- Air
- 27°C
Tue 3 · 76 out of 100
- Sea
- 0.8 m
- Wind
- 16 kn
- Gusts
- 22kn
- Air
- 26°C
Wed 4 · 80 out of 100
- Sea
- 0.5 m
- Wind
- 9 kn
- Gusts
- 13kn
- Air
- 27°C
Thu 5 · 81 out of 100
- Sea
- 0.4 m
- Wind
- 7 kn
- Gusts
- 10kn
- Air
- 27°C
Fri 6 · 75 out of 100
- Sea
- 0.8 m
- Wind
- 17 kn
- Gusts
- 23kn
- Air
- 26°C
Sat 7 · 67 out of 100
- Sea
- 1.0 m
- Wind
- 23 kn
- Gusts
- 32knboats in
- Air
- 25°C
Sun 8 · 76 out of 100
- Sea
- 0.8 m
- Wind
- 16 kn
- Gusts
- 23kn
- Air
- 25°C
Tap a day for sea, wind and water. Full forecast
Forecast: next 9 days
Full forecast- Mon 281, good
- Tue 376, good
- Wed 480, good
- Thu 581, good
- Fri 675, good
- Sat 767, good
- Sun 876, good
- Mon 974, good
- Tue 1077, good
The site in five facts
- Down to 35 mits deepest
- From a boathow you get in
- Experienced / deepexperienced divers only
- Water 26 °C3 mm wetsuit
- Faces NWswell from there reaches it
Full forecast
every day, every number
The score doesn't know currents, the visibility on the day or your certification.
Suits experienced divers only, as a dive guide states it. Scored for experienced divers.
| Day | Score | Sea | Wind | Gusts | Air |
|---|---|---|---|---|---|
| Mon 2Nov | 81, good | 0.4 m | 6 kn | 9kn | 27°C |
| Tue 3Nov | 76, good | 0.8 m | 16 kn | 22kn | 26°C |
| Wed 4Nov | 80, good | 0.5 m | 9 kn | 13kn | 27°C |
| Thu 5Nov | 81, good | 0.4 m | 7 kn | 10kn | 27°C |
| Fri 6Nov | 75, good | 0.8 m | 17 kn | 23kn | 26°C |
| Sat 7Nov | 67, good | 1.0 m | 23 kn | 32knboats in | 25°C |
| Sun 8Nov | 76, good | 0.8 m | 16 kn | 23kn | 25°C |
| Mon 9Nov | 74, good | 0.8 m | 18 kn | 24kn | 25°C |
| Tue 10Nov | 77, good | 1.0 m | 15 kn | 22kn | 25°C |
Sea is the waves near the site, in metres; wind and gusts in knots. "Boats in": gusts that keep dive boats in. More
Tide
- Mon 2 NovLow 05:49 −0.7 mHigh 12:59 +0.4 mLow 18:28 −0.0 m
- Tue 3 NovHigh 00:03 +0.4 mLow 07:13 −0.6 mHigh 14:11 +0.5 mLow 20:05 −0.2 m
- Wed 4 NovHigh 01:50 +0.4 mLow 08:29 −0.5 mHigh 15:04 +0.5 mLow 21:13 −0.4 m
Local clock times; heights about mean sea level. On open coasts the times are usually within a quarter of an hour; in bays, estuaries and on the Gulf of Mexico they can be an hour or more out. Slack water, the safest time to dive where there is current, is about half an hour either side of each high and low. Tide: EOT20 global ocean tide model, Hart-Davis et al. 2021, DGFI-TUM (doi:10.17882/79489), CC BY 4.0. Times and heights computed by us. A model, not a tide table: check a local table before you go.
Forecast updated . It refreshes every three hours. Forecast data: ECMWF, DWD, Météo-France and NOAA, served by Open-Meteo.com (CC BY 4.0). Changed by us. Generated using E.U. Copernicus Marine Service Information.
Map
the site and its town
L字アーチ on Google Maps · Directions
Each place wears its best day on these dates: green good, amber fair, pale red poor, as the key says.
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One finger scrolls the page; two fingers move the map. Pins are our own positions. Map OpenFreeMap, © OpenMapTiles, data © OpenStreetMap contributors.
About
the place in full, sources, credits
About L字アーチ
A cave dive. It goes down to 35 m. You get in from a boat. It suits experienced divers only, as a dive guide states it. The coast faces NW: swell from the NW reaches it, and wind from the SE blows out to sea. No dive centre within 10 km, the nearest 11 km away. The sea is about 23°C in January, its coldest month (5 mm wetsuit), and 30°C in August, its warmest (rash vest or 1 to 2 mm). The town to stay in is Hirara. Within 5 km we also list 3 dive sites.
- What it is Cave.
- How deep Down to 35 m.
- Getting in From a boat.
- Who it suits Suits experienced divers only, as a dive guide states it.
- Dive centres No dive centre within 10 km, the nearest 11 km away.
Water about 26°C: 3 mm wetsuit. Typical sea temperature for the time of year, not a forecast.
Visibility about 20 m. Typical for the time of year, estimated from ten years of NASA satellite water clarity, not a forecast. Clearest in Mar, Apr, May, Jun, Jul and Aug (about 25 m).
The score is the conditions only: the journey, the price and the partners never change it (how we score, how we earn).
Rough cost (estimate): about US$1,310–US$2,540 each
about US$1,310–US$2,540 each · 6 nights, 2 sharing: flights, hire car, stay, food.
Our estimate from typical public prices, not a quote: check the real prices before you book (where they come from). Prices are about, in US Dollar (USD): our pound figures at the European Central Bank's rate of 30 October 2026.
How we worked it out
| What | How we worked it out | Each |
|---|---|---|
| Flights | return ORD to ISG, estimated from distance and season, changing at HKG, full-service airlines, with a hold bag | about US$757–US$1,570 |
| Hire car | 6 days, shared | about US$107–US$174 |
| Stay | 6 nights, a mid-range double, shared | about US$208–US$348 |
| Food | 7 days eating out | about US$234–US$442 |
| Total | about US$1,310–US$2,540 |
Guided dives are not priced yet: we have no sourced price, so it is not in it. Prices from public sources, checked in 2026.
Where to stay: Hirara
28 min by car · 18 places to stay
about US$80/nightcountry average
About Hirara its beds, food and every spot near it
About US$80 a night is our estimate of the country's average 2-star double room that month: not each town's price, and not a quote. Drives are estimates. Prices are about, in US Dollar (USD): our pound figures at the European Central Bank's rate of 30 October 2026.
Getting there: about 27h 20m
About 27h 20m door to door from Chicago
Fly ORD → ISG, changing at Hong Kong International Airport (HKG), then 2h 10m by road
Flights ORD → ISG on your dates · Skyscanner
An estimate, one way; the journey never changes the score.
In the water
Dives and courses in Hirara · GetYourGuideDive gear hire in Hirara · GetYourGuide
Dive centres nearby
MARINECLUB 11 km
Pipeline 13 km
シギラ ビーチハウス 24 km
The nearest named dive centres and shops within 25 km, in a straight line; training agencies where the map states them. Listings, not a recommendation. Dive centres: © OpenStreetMap contributors (ODbL). Credits
What you might see
Too few open records near this site to list its animals. Ask a dive centre what you are likely to see.
This week's visibility, the current and the life no free forecast gives. Ask a dive centre before you book.
Saved: this link opens the same trip
The link holds the trip itself: nothing about you is kept. Check the forecast again before you book.