San Antonio (CLSAI) — marine weather & port guide
San Antonio is a port in Chile at 33°36.0′S 71°36.0′W. Today (Aug 3): NNE wind 6–8 kn, waves 2.2–2.5 m, from the ECMWF IFS run 2026-08-03 12z. The live chart on this page shows current conditions and plans weather-optimized departures from this harbor.
Port facts (NGA World Port Index)| Position | 33°36.0′S 71°36.0′W |
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| UN/LOCODE | CLSAI |
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| Harbor size | Small |
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| Harbor type | Coastal breakwater harbor |
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| Shelter | Good |
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| Channel depth | 23 m |
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| Anchorage depth | 23 m |
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| Tide range | 4 m |
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| Pilotage | Compulsory |
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| Time zone | America/Santiago |
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10-day marine forecast — San Antonio
| Date | Wind | Gusts | Waves |
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| NNE 6–8 kn | 11 kn | 2.2–2.5 m |
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| SW 3–15 kn | 19 kn | 2.1–2.4 m |
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| SSW 6–16 kn | 21 kn | 2.0–2.3 m |
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| SSW 14–20 kn | 26 kn | 2.2–3.3 m |
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| S 3–23 kn | 31 kn | 1.8–3.0 m |
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| S 10–13 kn | 16 kn | 2.1–3.9 m |
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| S 15–20 kn | 25 kn | 3.5–3.8 m |
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| S 13–13 kn | 22 kn | 2.8–2.8 m |
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| S 14–14 kn | 20 kn | 1.9–1.9 m |
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| S 19–19 kn | 26 kn | 1.8–1.8 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 is the weather at San Antonio right now?
As of the ECMWF IFS run 2026-08-03 12z: NNE wind 6–8 kn, waves 2.2–2.5 m. The 10-day outlook is in the forecast table on this page and updates with each model cycle.
How big is the harbor at San Antonio?
San Antonio is classed as a small harbor (coastal breakwater harbor), with good shelter in the NGA World Port Index.
How deep is the approach to San Antonio?
Per the NGA World Port Index, the entrance channel carries about 23 m and anchorage depths run about 23 m. Verify against current official charts before entry.
What restricts entry to San Antonio?
Entry is affected by tidal windows, heavy swell. Check the live forecast on this page and official notices before approach.