Muroran Ko to Yokosuka — sea route & marine weather
The sea route from Muroran Ko (JPMUR) to Yokosuka (JPYOS) is about 547 nm — about 2 days at 10 kn. Along the route today (Aug 3): SE wind 13–26 kn, waves 2.1–4.0 m. The baseline track is drawn on the chart; Calculate replans it for your vessel and live weather.
Passage facts| Sea-route distance | 547 nm |
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| Passage time at 10 kn | about 2 days |
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| Great-circle distance | 428 nm |
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| Muroran Ko | 42°21.0′N 140°58.0′E |
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| Yokosuka | 35°17.0′N 139°40.0′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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| SE 13–26 kn | 34 kn | 2.1–4.0 m |
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| SE 10–25 kn | 33 kn | 2.6–4.1 m |
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| SSE 5–22 kn | 31 kn | 2.2–3.6 m |
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| SE 2–12 kn | 15 kn | 1.7–2.7 m |
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| S 2–12 kn | 14 kn | 1.5–2.3 m |
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| NNW 1–15 kn | 19 kn | 1.5–2.1 m |
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| ENE 10–19 kn | 23 kn | 2.1–2.8 m |
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| ENE 16–23 kn | 33 kn | 2.8–3.9 m |
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| WSW 3–19 kn | 30 kn | 1.8–2.8 m |
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| SSE 1–9 kn | 13 kn | 1.5–1.5 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 Muroran Ko to Yokosuka by sea?
The water route is 547 nm (1,014 km), computed on WXMarine's maritime routing network. The same distance applies on the return passage from Yokosuka to Muroran Ko.
How long does the passage from Muroran Ko to Yokosuka take?
about 2 days 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 Muroran Ko and Yokosuka today?
Along the route today, per the ECMWF IFS run 2026-08-03 12z: SE wind 13–26 kn, waves 2.1–4.0 m. The day-by-day table on this page covers the next 10 days.