NOAA Electronic Navigational Charts (ENC)

Use in your agent

Confirm NOAA ENC overview and User Agreement reachability. Checked against the provider's documentation on Nov 5, 2026.

Access

• No key. Download individual or regional ENC cells from Coast Survey pages after accepting the User Agreement where prompted.

Request

curl -I 'https://nauticalcharts.noaa.gov/charts/noaa-enc.html'

Format

HTML ENC product overview; User Agreement HTML; ENC download index.

Load into pandas and Parquet

Needs Python 3 with requests, pandas and pyarrow.

"""NOAA ENC page probe -> pandas -> Parquet."""
import pandas as pd
import requests

UA = {"User-Agent": "SignalLabCheck/1.0"}
rows = []
for url in [
    "https://nauticalcharts.noaa.gov/charts/noaa-enc.html",
    "https://charts.noaa.gov/ENCs/ENC_Agreement.shtml",
    "https://charts.noaa.gov/ENCs/ENCs.shtml",
]:
    r = requests.get(url, headers=UA, timeout=60, allow_redirects=True)
    rows.append({"url": url, "status": r.status_code, "bytes": len(r.content), "final_url": r.url})
df = pd.DataFrame(rows)
df.to_parquet("noaa_enc_pages.parquet", index=False)
print(df)

Run by us on 2026-11-05 (python 3 | pandas | pyarrow | requests). Result: ENC overview, User Agreement and ENC download pages returned HTTP 200 on 2026-11-05; overview states Coast Survey ENCs are free.

Limits

• Not stated numeric rate limit.
• Full national ENC set is large; this skill only probes documentation pages.

Quirks

• Weekly Notice to Mariners updates; the User Agreement notes that timing of their availability is not assured.
• Redistributed ENCs are not official for federal carriage unless via a certified distributor.

Terms and attribution

• User Agreement permits download, use and redistribution without payment to NOAA, with the official-product caveats stated there.

Sources

• https://nauticalcharts.noaa.gov/charts/noaa-enc.html: “NOAA ENCs downloaded directly from these Coast Survey websites are free.”
• https://charts.noaa.gov/ENCs/ENC_Agreement.shtml: “You may download, use, and redistribute them without restriction, and without payment to NOAA, except as noted herein.”