# OpenCPN/OpenCPN

A concise ChartPlotter/Navigator. A cross-platform ship-borne GUI application supporting * GPS/GPDS Postition Input * BSB Raster Chart Display * S57 Vector ENChart Display * AIS Input Decoding * Waypoint Autopilot Navigation

Repository: https://github.com/OpenCPN/OpenCPN
Canonical: https://ross.abutalabs.com/products/opencpn
Homepage: https://opencpn.org/
Language: C
License: GPL-2.0
License Family: copyleft
Topics: ais, autopilot, boating, chartplotter, charts, gps, grib, grib2, gshhs, marine, nautical, nautical-charts, navigation, nmea, nmea0183, sailing, signalk, weather, ecdis, nmea2000
Last push: 2026-08-26T11:56:36+00:00

## Health v2 (maintenance only)
Score: 83/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 99, release rhythm 54, longevity 100
- inputs: {"age_days": 6056, "days_push": 7, "days_rel": 147, "gap_med": 124.0, "n_releases_24m": 5}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1479, forks 619 (observed 2026-08-28T04:04:50.708540+00:00)

## What it is
OpenCPN is a cross-platform, open-source chartplotter and navigation application for vessels, displaying BSB raster and S57 vector charts. It ingests GPS position, AIS targets, and NMEA/SignalK data, and supports waypoint autopilot navigation.

## Use cases
- display nautical charts while sailing
- track AIS vessel targets onboard
- connect GPS to a marine navigation display
- navigate a boat with raster and vector charts
- feed waypoints to an autopilot
- view GRIB weather overlays at sea
- replace a commercial chartplotter with open-source software

## When to choose
- you need a helm-visible, real-time navigation interface on Windows, macOS, Linux, or Android
- you work with BSB raster or S57 ENC vector charts
- you want to integrate NMEA 0183/2000, SignalK, AIS, or GRIB weather data

## When to avoid
- you mainly need offline route planning, tide/current prediction, or logging rather than live navigation
- you need a certified ECDIS for commercial regulatory compliance
- you need a mobile-first or web-based chart viewer

## Facets
- artifact type: application
- maturity: stable
- function: gui, graphics, geospatial, data-visualization
- domain: cross-platform, weather
- platform: windows, cross-platform
- tags: chartplotter, marine-navigation, gps, ais, nmea, sailing, nautical-charts, autopilot, s57, bsb-raster, signalk, grib-weather, ecdis, real-time, maps, macos, linux, android, desktop

## Member repositories
- OpenCPN/OpenCPN (main) score 83

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:04:50.708540+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T04:34:17.515885+00:00, confidence not recorded.
  - readme: https://github.com/OpenCPN/OpenCPN (fetched 2026-08-28T04:04:50.708540+00:00, sha 0dea0a32a62f)
- Data as of 2026-08-30T08:39:29.467469+00:00.