Is This Coordinate on Water or Land? • GPS
Free online coordinate land vs. water checker. Verify GPS coordinates against global oceans, continental landmasses.
High-Clarity Equirectangular World Map. Click any point to test or inspect external map tiles:
Classification Result
| Target Latitude: | -48.8767° |
| Target Longitude: | -123.3933° |
| Designated Basin / Region: | South Pacific Ocean |
| Geographic Type: | Open Ocean |
| Hemisphere: | Southern & Western Hemisphere |
Batch Coordinate Land / Water QA
Paste comma-separated or tab-separated latitude and longitude pairs (one per line). Ideal for validating sensor logs, delivery addresses, and drone telemetry.
Geodetic & Maritime Classification Standards
Territorial Waters & UNCLOS
Under the United Nations Convention on the Law of the Sea (UNCLOS), sovereign territorial waters extend up to 12 nautical miles (22.2 km) from coastal baselines. Beyond territorial seas lie the Contiguous Zone (up to 24 NM) and Exclusive Economic Zone (EEZ, up to 200 NM).
- Internal Waters: Ports, bays, rivers, and landward lakes.
- Territorial Sea: 12 nautical miles sovereign maritime zone.
- High Seas: International waters open to all nations.
Common GIS Coordinate Pitfalls
In geospatial software engineering, coordinate errors are a leading cause of data corruption. Common failure modes include:
- Axis Inversion: Storing `(Lng, Lat)` instead of `(Lat, Lng)`, placing inland addresses into the ocean.
- Missing Negative Signs: Omitting western longitude or southern latitude signs.
- Null Island Trap: Defaulting uninitialized database coordinates to `0.0, 0.0`.
About this tool
How to use it
- Enter any GPS latitude (-90 to +90) and longitude (-180 to +180) into the input fields, or click anywhere on the interactive World Canvas map.
- Alternatively, select one of the iconic geographical presets (Point Nemo, Mariana Trench, Null Island, Bermuda Triangle, or Sahara Desert).
- Click 'Analyze Coordinate' to determine whether the point falls over open ocean, inland sea, major freshwater lake, or terrestrial landmass.
- Inspect the classification badge, designated water basin or continental zone, and approximate distance to nearest shoreline.
- Switch to the 'Batch Validator' tab to check dozens of coordinate pairs simultaneously via CSV or newline paste.
Why it matters
Validating whether coordinates fall on land or water is a critical data hygiene step in geospatial development, shipping logistics, drone telemetry, asset tracking, and sensor sanity testing. Erroneous coordinates (such as swapped lat/long or inverted signs) frequently place terrestrial addresses in the middle of oceans.
When to use it
Use this tool to verify GIS databases, validate GPS breadcrumbs before geofencing alerts, test reverse geocoder fallbacks, or sanity-check user-submitted coordinates in software applications.
Common questions
What is 'Null Island'?
Null Island is the fictional location at 0°N, 0°E in the Gulf of Guinea off West Africa, where the equator intersects the prime meridian. It is the most common destination for unhandled null or 0,0 GPS coordinates in software bugs.
How does this tool classify land versus water client-side?
The tool uses a high-efficiency client-side continental landmask and polygon ray-casting algorithm with bounding boxes for global landmasses, major archipelago chains, inland seas, and open ocean basins.
Are freshwater lakes classified as water or land?
Major global freshwater bodies—such as the Laurentian Great Lakes (Superior, Michigan, Huron, Erie, Ontario), Caspian Sea, Lake Victoria, Lake Baikal, and Lake Tanganyika—are explicitly detected and classified as inland water.
What geodetic datum is used for coordinates?
Coordinates follow the standard WGS84 (World Geodetic System 1984) ellipsoid used by modern GPS and mapping engines worldwide.
What is Point Nemo?
Point Nemo (48°52.6′S 123°23.6′W) in the South Pacific Ocean is the oceanic pole of inaccessibility—the point on Earth farthest from any landmass (approx. 2,688 km / 1,670 mi from the nearest islands).