NOAA S-57 chart cell
Back River
US4MD1FC
- Usage band
- Approach · code 4
- Current edition
- 1.0
- Features
- 51
- S-57 layers
- 15
- Published
- Jul 22, 2025
- Manifest updated
- Jun 22, 2026, 2:51 PM UTC
Coverage
- North
- 39.60000° N
- South
- 39.30000° N
- West
- 76.80000° W
- East
- 76.50000° W
- Center
- 39.45000° N, 76.65000° W
- Bounds area
- 251 sq nm
- Feature density
- 0.2036 / sq nm
Chart Statistics
15 largest layers shown
- Average features per layer
- 3.4
- Smallest layer
- 1
- Largest layer
- 14
- Area sq km
- 859
- Features per sq km
- 0.05935
- COALNE Coastline 14
- LNDRGN Land region 8
- BRIDGE 7
- BUAARE 4
- CBLOHD 3
- DEPARE Depth area 2
- LNDARE Land area 2
- M_QUAL Data quality 2
- MAGVAR Magnetic variation 2
- SEAARE Sea area 2
- BUISGL 1
- M_COVR Coverage 1
- M_NPUB 1
- M_NSYS 1
- RIVERS River 1
Nearby Chart Cells
Approach usage band
Current Edition Files
The NOAA ZIP archive is the upstream source for this chart cell; the other files are Open Ships generated derivatives for web and GIS use.
- Original NOAA ZIP archive https://www.charts.noaa.gov/ENCs/US4MD1FC.zip
- S-57 cell https://charts.openships.ai/noaa/s57/approach/US4MD1FC/1.0/US4MD1FC.000
- GeoJSON https://charts.openships.ai/noaa/s57/approach/US4MD1FC/1.0/US4MD1FC.geojson
- GeoParquet https://charts.openships.ai/noaa/s57/approach/US4MD1FC/1.0/US4MD1FC.parquet
- Metadata JSON https://charts.openships.ai/noaa/s57/approach/US4MD1FC/1.0/metadata.json
Editions
| Edition | Published | Metadata |
|---|---|---|
| 1.0 | Jul 22, 2025 | metadata.json |