Brest to Saint-Nazaire — sea route & marine weather
The sea route from Brest (FRBES) to Saint-Nazaire (FRSNR) is about 153 nm — about 15 hours at 10 kn. Along the route today (Sep 13): W wind 3–6 kn, waves 0.9–1.5 m. The baseline track is drawn on the chart; Calculate replans it for your vessel and live weather.
Passage facts| Sea-route distance | 153 nm |
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| Passage time at 10 kn | about 15 hours |
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| Great-circle distance | 114 nm |
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| Brest | 48°24.0′N 4°29.0′W |
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| Saint-Nazaire | 47°17.0′N 2°12.0′W |
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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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| W 3–6 kn | 13 kn | 0.9–1.5 m |
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| NE 1–5 kn | 9 kn | 0.6–1.5 m |
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| NW 1–14 kn | 22 kn | 0.6–1.3 m |
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| NW 6–13 kn | 20 kn | 1.2–2.2 m |
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| W 4–15 kn | 19 kn | 1.2–2.4 m |
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| WNW 6–13 kn | 17 kn | 1.4–2.5 m |
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| SW 6–10 kn | 12 kn | 1.0–2.5 m |
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| N 2–5 kn | 10 kn | 0.9–1.5 m |
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| 3–5 kn | 11 kn | 0.8–1.6 m |
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| NNE 6–7 kn | 15 kn | 0.7–1.3 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 Brest to Saint-Nazaire by sea?
The water route is 153 nm (284 km), computed on WXMarine's maritime routing network. The same distance applies on the return passage from Saint-Nazaire to Brest.
How long does the passage from Brest to Saint-Nazaire take?
about 15 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 Brest and Saint-Nazaire today?
Along the route today, per the ECMWF IFS run 2026-09-13 12z: W wind 3–6 kn, waves 0.9–1.5 m. The day-by-day table on this page covers the next 10 days.