Sumatra and Java · Today

Batu Karas

Updated Wed, Sep 23, 6:40 AM GMT+7

When to go

Around 5:00 PM

Looks good · Low confidence

5.5–5.5 ft · Offshore waves · not face height

Wind: 3.9 kt · cross-shore

Forecast details

Light wind should keep the water smoother.

Other wind windows

Plan around the wind

The best available upcoming daylight wind sample to compare with the wave evidence. This compares wind only; wave size, tide suitability, and hazards can change your choice.

7:00 AM–9:00 AM · Asia/Jakarta
Light wind · up to 5.9 kt · reported gusts up to 14.6 kt
Offshore waves: 5.4–5.5 ft across the period. Surf height unavailable. Tide data unavailable.
Wind source time: Sep 23, 6:30 AM GMT+7. This is not the model run issue time.

How these periods are chosen

The planner prefers three consecutive hourly samples covering two daylight hours, but retains shorter one- or two-sample evidence when that is all the forecast provides. Light wind means at most 6 kt. Moderate offshore means at most 12 kt from land toward the sea when shore orientation is verified. Strong wind or known gusts of 20 kt or more remain visible as cautions instead of making the entire comparison disappear. These are comparison labels, not locally tested surf-quality or safety ratings. Missing gusts remain unknown. Terrain shelter, currents, closures, and your ability are not assessed.

Forecast confidence

Returned marine grid point is 6.5 km from the mapped spot. Provider grid resolution is not established for this response.
Reference model hour: 0 hours from now; historical residuals do not measure forecast lead-time error.
No accepted local model for these inputs: missing history, unsupported direction/period/height, or failed historical validation.
Tide unavailable: assessment incomplete, especially at shallow reef breaks.
A mapped coordinate does not establish nearshore grid resolution or terrain/shelter accuracy.

Wind NE 4.1 kt

Tide Unavailable

Wave, wind and tide details

Offshore model swellS 5.4 ft @ 11sValid 2026-09-23 07:00 · Asia/JakartaMarine grid -7.7917, 108.4584 · offshore model, not a local measurement

Offshore model sea5.4 ft @ 13.1sSignificant wave height including wind waves and swell; not breaking surfValid 2026-09-23 07:00 · Asia/Jakarta

Model windNE 4.1 ktonshoreValid 2026-09-23 07:00 · Asia/Jakarta3.8 kt onshore component

TideUnavailableunavailableNo verified local tide station connected; no tide height estimated

BMKG Samudra Hindia selatan Jawa Barat7.2–7.5 ftBMKG offshore significant wave height; not breaking surfIssued Sep 22, 7:00 PM GMT+7

Surf height unavailable. Coastal and offshore waves are not breaking-wave heights.

Surf and wind

Recommended window: No recommended window

Breaking surf is not reliably resolved. Hourly offshore swell and wind inputs are listed below.

Hourly forecast

Hourly surf forecast for Batu Karas
Time	Wind	Tide	Offshore swell
12 AM	NNW 1 ktonshore	Unavailableunavailable	S 5.1 ft @ 11s
1 AM	NNW 1.3 ktonshore	Unavailableunavailable	S 5.2 ft @ 11s
2 AM	N 1.7 ktonshore	Unavailableunavailable	S 5.2 ft @ 11s
3 AM	N 1.8 ktonshore	Unavailableunavailable	S 5.2 ft @ 11s
4 AM	NNE 2.6 ktonshore	Unavailableunavailable	S 5.3 ft @ 11s
5 AM	NE 3.2 ktonshore	Unavailableunavailable	S 5.4 ft @ 11s
6 AM	NE 4 ktonshore	Unavailableunavailable	S 5.4 ft @ 11s
7 AM	NE 4.1 ktonshore	Unavailableunavailable	S 5.4 ft @ 11s
8 AM	ENE 5.4 ktonshore	Unavailableunavailable	S 5.4 ft @ 11s
9 AM	ENE 5.9 ktcross-shore	Unavailableunavailable	S 5.5 ft @ 11s
10 AM	E 6.1 ktcross-shore	Unavailableunavailable	S 5.5 ft @ 11s
11 AM	ESE 6.6 ktcross-shore	Unavailableunavailable	S 5.5 ft @ 11s
Noon	ESE 7 ktcross-shore	Unavailableunavailable	S 5.5 ft @ 11s
1 PM	ESE 7.1 ktcross-shore	Unavailableunavailable	S 5.5 ft @ 11s
2 PM	ESE 7 ktcross-shore	Unavailableunavailable	S 5.5 ft @ 11s
3 PM	ESE 5.9 ktcross-shore	Unavailableunavailable	S 5.5 ft @ 11s
4 PM	ESE 4.7 ktcross-shore	Unavailableunavailable	S 5.5 ft @ 11s
5 PM	E 3.9 ktcross-shore	Unavailableunavailable	S 5.5 ft @ 11s
6 PM	ENE 3.4 ktonshore	Unavailableunavailable	S 5.4 ft @ 11s
7 PM	ENE 3.2 ktcross-shore	Unavailableunavailable	S 5.4 ft @ 11s
8 PM	E 3.9 ktcross-shore	Unavailableunavailable	S 5.4 ft @ 11s
9 PM	ENE 4.1 ktonshore	Unavailableunavailable	S 5.4 ft @ 11s
10 PM	NE 4.7 ktonshore	Unavailableunavailable	S 5.4 ft @ 10s
11 PM	NE 4.8 ktonshore	Unavailableunavailable	S 5.4 ft @ 10s

12 AMUnavailable

WindNNW 1 ktonshoreTideUnavailableunavailableOffshore swellS 5.1 ft @ 11s

1 AMUnavailable

WindNNW 1.3 ktonshoreTideUnavailableunavailableOffshore swellS 5.2 ft @ 11s

2 AMUnavailable

WindN 1.7 ktonshoreTideUnavailableunavailableOffshore swellS 5.2 ft @ 11s

3 AMUnavailable

WindN 1.8 ktonshoreTideUnavailableunavailableOffshore swellS 5.2 ft @ 11s

4 AMUnavailable

WindNNE 2.6 ktonshoreTideUnavailableunavailableOffshore swellS 5.3 ft @ 11s

5 AMUnavailable

WindNE 3.2 ktonshoreTideUnavailableunavailableOffshore swellS 5.4 ft @ 11s

6 AMUnavailable

WindNE 4 ktonshoreTideUnavailableunavailableOffshore swellS 5.4 ft @ 11s

7 AMUnavailable

WindNE 4.1 ktonshoreTideUnavailableunavailableOffshore swellS 5.4 ft @ 11s

8 AMUnavailable

WindENE 5.4 ktonshoreTideUnavailableunavailableOffshore swellS 5.4 ft @ 11s

9 AMUnavailable

WindENE 5.9 ktcross-shoreTideUnavailableunavailableOffshore swellS 5.5 ft @ 11s

10 AMUnavailable

WindE 6.1 ktcross-shoreTideUnavailableunavailableOffshore swellS 5.5 ft @ 11s

11 AMUnavailable

WindESE 6.6 ktcross-shoreTideUnavailableunavailableOffshore swellS 5.5 ft @ 11s

NoonUnavailable

WindESE 7 ktcross-shoreTideUnavailableunavailableOffshore swellS 5.5 ft @ 11s

1 PMUnavailable

WindESE 7.1 ktcross-shoreTideUnavailableunavailableOffshore swellS 5.5 ft @ 11s

2 PMUnavailable

WindESE 7 ktcross-shoreTideUnavailableunavailableOffshore swellS 5.5 ft @ 11s

3 PMUnavailable

WindESE 5.9 ktcross-shoreTideUnavailableunavailableOffshore swellS 5.5 ft @ 11s

4 PMUnavailable

WindESE 4.7 ktcross-shoreTideUnavailableunavailableOffshore swellS 5.5 ft @ 11s

5 PMUnavailable

WindE 3.9 ktcross-shoreTideUnavailableunavailableOffshore swellS 5.5 ft @ 11s

6 PMUnavailable

WindENE 3.4 ktonshoreTideUnavailableunavailableOffshore swellS 5.4 ft @ 11s

7 PMUnavailable

WindENE 3.2 ktcross-shoreTideUnavailableunavailableOffshore swellS 5.4 ft @ 11s

8 PMUnavailable

WindE 3.9 ktcross-shoreTideUnavailableunavailableOffshore swellS 5.4 ft @ 11s

9 PMUnavailable

WindENE 4.1 ktonshoreTideUnavailableunavailableOffshore swellS 5.4 ft @ 11s

10 PMUnavailable

WindNE 4.7 ktonshoreTideUnavailableunavailableOffshore swellS 5.4 ft @ 10s

11 PMUnavailable

WindNE 4.8 ktonshoreTideUnavailableunavailableOffshore swellS 5.4 ft @ 10s

Tide

Local tide station unavailable

Tide predictions are unavailable for this period.

About this spot

Model-grid forecast requested at the mapped coordinate; reef, headland, and nearshore transformations are unresolved. Beach and point break. Named-break coordinate and bay-facing orientation reviewed for BMKG South West Java offshore-area assignment.

Mapped spot coordinate: -7.75, 108.5.

Java · south coast of West Java · Ocean-facing bearing 22.5° · Location provenance

Model request point: Sumatra and Java (-7.75, 108.5). Model output times describe valid conditions; the provider does not expose the model run issue time in this response.

Forecast sources

Data coverage 3/6 sources

Source availability is not forecast accuracy. Where an empirical model passes historical testing, its error and interval coverage are shown above. Source count cannot increase that confidence.

Coverage tier C · INDONESIA · spot-level model point

BMKG Samudra Hindia selatan Jawa Barat
BMKG Samudra Hindia selatan Jawa Barat; BMKG offshore significant wave height; not breaking surfCurrentSep 22, 7:00 PM GMT+7
The Buoy API
Normalized nearest-buoy discovery and readings; market adapter or station mapping not connectedUnavailableNo source time
WorldTides API
Tide predictions and station lookup; market adapter or station mapping not connectedUnavailableNo source time
Open-Meteo Marine API
1 of 1 configured model points availableCurrentSep 23, 6:30 AM GMT+7
Open-Meteo Weather API
1 of 1 configured model points availableCurrentSep 23, 6:30 AM GMT+7
Copernicus Marine Global Ocean Waves
Independent wave-model backend and cross-check; market adapter or station mapping not connectedUnavailableNo source time
Surf-Forecast public pages
Spot discovery and break-specific HTML fallbackNot applicableNo source time
Surfline public spot pages
Break-specific comparison, cams, and metadataNot applicableNo source time

How best guesses are made

Best guesses combine usable wave and wind evidence, with qualitative confidence and specific limitations. A missing tide or local surf-height model does not prevent useful guidance. Tide levels use the named station datum; their effect at this break remains uncertain. Wind direction is relative to the mapped beach orientation, without calibrated terrain or shelter effects. The comparison is a heuristic, not a measured quality rating.