Data sources
CoastFinder covers the coast of North and South Carolina, with more regions to come.
Every position and depth in the app comes from one of the sources below. The app lists them under Data sources in More, and every detail card names the source of that feature.
Charts and depths
| Source | What it provides | License | Link |
|---|---|---|---|
| NOAA ENC Direct to GIS (Office of Coast Survey) | The electronic navigational charts: coastline, islands, shoals, reefs, charted wrecks, soundings and depth contours. | US Government work, public domain (not for navigation) | encdirect.noaa.gov |
| NOAA NCEI bathymetry (upstream of ENC soundings) | The survey soundings behind the chart depths and the seafloor grid. | US Government work, public domain | ncei.noaa.gov |
Lights
| Source | What it provides | License | Link |
|---|---|---|---|
| US Coast Guard Light List, weekly XML | Surveyed positions of lighthouses and other aids to navigation, with their heights and light characteristics. | US Government work, public domain | Volume II, District 5 Volume III, District 7 |
Tides
| Source | What it provides | License | Link |
|---|---|---|---|
| NOAA CO-OPS tide predictions (MLLW) | Predicted tide heights at the nearest station, used to estimate the depth over a feature right now. | US Government work, public domain | tidesandcurrents.noaa.gov |
Wrecks
| Source | What it provides | License | Link |
|---|---|---|---|
| NOAA AWOIS wreck database (NC DMF ArcGIS copy, July 2013) | Wreck names, loss details and a position-quality grade for each record, redistributed by the NC Division of Marine Fisheries. | US Government work, public domain; retired NOAA dataset redistributed by NC DMF | NC DMF feature service |
| Curated records | A small number of wrecks checked by hand against NOAA, state, National Park Service and dive references. | Curated by the CoastFinder team from public NOAA AWOIS, NC DMF reef guide and NPS sources | nauticalcharts.noaa.gov |
Artificial reefs
| Source | What it provides | License | Link |
|---|---|---|---|
| NC Division of Marine Fisheries Artificial Reef Guide | North Carolina reef sites, with their AR numbers, official names and footprints. | NC DEQ public data, reference only; attribute NCDENR - Division of Marine Fisheries | NC DMF Reef Guide |
| SC DNR Marine Artificial Reef coordinates (ArtReef2021) | South Carolina reef structures and the buoys that mark each site. | SC DNR public data, available at no cost; last updated March 2021 | dnr.sc.gov |
Places and landmarks
| Source | What it provides | License | Link |
|---|---|---|---|
| OpenStreetMap via Overpass API | Islands, lighthouses and other landmarks along the shore. | ODbL 1.0, © OpenStreetMap contributors | openstreetmap.org/copyright |
Maps in the app and on this website
| Source | What it provides | License | Link |
|---|---|---|---|
| OpenFreeMap | The background map in the app's Map tab and in the Viewpoint map on this website. Free, with no account or key. | Attribution: OpenFreeMap, © OpenMapTiles, data from OpenStreetMap (ODbL) | openfreemap.org |
| MapLibre GL JS | The map viewer in the app and on this website. | BSD-3-Clause | maplibre.org |
About OpenStreetMap
OpenStreetMap is the Wikipedia of maps: a map of the world made by volunteers, free for anyone to use. Anyone can add a missing lighthouse or correct the name of an island. Changes reach CoastFinder the next time a region is rebuilt. If you would like to help, openstreetmap.org/fixthemap explains how.
The region packs
A region pack is the data file behind each region in the app, combining the sources above. Because the packs include OpenStreetMap data, the region packs are made available under the Open Database License 1.0; the data from OpenStreetMap remains © OpenStreetMap contributors. The license covers the packs as a database. It does not cover the CoastFinder app, its design or the descriptions written for it.
When something is wrong
Tell us from the app. At the bottom of every detail card, Know this spot? Help improve it sends us which feature, which region pack and which app version you mean, so we can trace it back to the source. For something the app does not have yet, use Tell us about it in Search or under More. More on the Support page.
How accurate is it?
It depends on the source, and the app keeps track of which is which. Every feature records where its position came from, how far off that position could be, and whether a person has checked it. A light from the Coast Guard Light List is good to about twenty meters and a charted symbol to about fifty; a wreck placed from an old loss report may be out by several kilometers. Where two sources disagree and nothing settles it, the feature is marked as disputed. When the doubt about a position is wide enough to matter from where you stand, the app draws a dashed span instead of a point, and depths that are interpolated rather than surveyed are labeled as such.