Jakarta, Java to Semarang — sea route & marine weather
The sea route from Jakarta, Java (IDJKT) to Semarang (IDSRG) is about 243 nm — about 24 hours at 10 kn. Along the route today (Aug 3): E wind 8–17 kn, waves 0.9–1.3 m. The baseline track is drawn on the chart; Calculate replans it for your vessel and live weather.
Passage facts| Sea-route distance | 243 nm |
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| Passage time at 10 kn | about 24 hours |
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| Great-circle distance | 217 nm |
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| Jakarta, Java | 6°6.0′S 106°53.0′E |
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| Semarang | 6°57.0′S 110°25.0′E |
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| Reference vessel | 4.5 m draft, 10 kn cruise |
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10-day marine forecast — along the route
| Date | Wind | Gusts | Waves |
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| E 8–17 kn | 21 kn | 0.9–1.3 m |
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| E 6–15 kn | 20 kn | 0.7–1.2 m |
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| E 9–15 kn | 21 kn | 0.7–1.1 m |
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| E 10–14 kn | 19 kn | 0.8–1.0 m |
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| E 9–16 kn | 20 kn | 0.7–1.1 m |
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| ESE 10–15 kn | 18 kn | 0.8–1.1 m |
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| ESE 12–14 kn | 18 kn | 0.9–1.1 m |
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| ENE 8–11 kn | 17 kn | 0.7–0.8 m |
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| ENE 10–13 kn | 20 kn | 0.7–0.8 m |
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| ENE 9–11 kn | 17 kn | 0.6–0.7 m |
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Forecast from the ECMWF IFS model run , waves from ECMWF WAM. Updated with each model cycle; the live chart below recalculates for your departure time and vessel.
Frequently asked
How far is it from Jakarta, Java to Semarang by sea?
The water route is 243 nm (451 km), computed on WXMarine's maritime routing network. The same distance applies on the return passage from Semarang to Jakarta, Java.
How long does the passage from Jakarta, Java to Semarang take?
about 24 hours at a 10 kn cruise. Scale by your own speed: at half the speed it takes about twice as long. The planner on this page recalculates for your vessel and live weather.
What is the weather between Jakarta, Java and Semarang today?
Along the route today, per the ECMWF IFS run 2026-08-03 12z: E wind 8–17 kn, waves 0.9–1.3 m. The day-by-day table on this page covers the next 10 days.