About
OpenCPN is a concise, robust, and completely free open-source Chart Plotter Navigation (CPN) application built specifically for marine use. Designed to be operated at the helm station while underway, it allows sailors, cruisers, and powerboaters to plan routes, monitor GPS position, and navigate with confidence using detailed nautical charts on everyday hardware — from a laptop to a Raspberry Pi or Android device. The software supports a wide range of vector and raster chart formats, including BSB/KAP, CM93, and S57/S63 ENC charts, giving mariners access to official and community-sourced charts for coastal and offshore navigation. A powerful plugin architecture lets users extend OpenCPN with AIS vessel tracking, weather overlays, radar integration, tide and current predictions, and more. Cross-platform by design, OpenCPN runs natively on Windows, macOS, Linux, Raspberry Pi, and Android, making it accessible on a wide variety of helm station setups. Route and waypoint management tools allow users to plan passages in advance and follow them with precision while underway. As a community-driven open-source project maintained since 2009, OpenCPN benefits from continuous contributions by developers and mariners worldwide. It is ideal for recreational sailors, offshore cruisers, racing navigators, and anyone seeking a capable, cost-free alternative to proprietary chartplotter software.
Key Features
- Chart Plotter Navigation: Plan and follow routes using a wide range of nautical chart formats including S57/S63, BSB/KAP, and CM93 vector and raster charts.
- Real-Time GPS Position Tracking: Connect to any NMEA-compatible GPS device to display your live position, speed, and heading directly on the chart.
- Extensible Plugin System: Enhance functionality with community-built plugins for AIS vessel tracking, weather overlays, radar display, tides, currents, and more.
- Cross-Platform Support: Runs natively on Windows, macOS, Linux, Raspberry Pi, and Android — fitting virtually any helm station configuration.
- Route & Waypoint Management: Create, edit, and follow detailed routes and waypoints, with full support for passage planning before and during a voyage.
Use Cases
- Offshore ocean passage planning and real-time navigation for bluewater sailors
- Coastal cruising with live GPS tracking and chart overlay on a laptop or tablet
- Inland waterway and river navigation using downloaded regional charts
- Sailboat racing with real-time position monitoring and mark-rounding waypoints
- Budget-friendly helm station setup using a Raspberry Pi or repurposed laptop as a dedicated chartplotter
Pros
- Completely Free & Open Source: OpenCPN costs nothing to download or use, and its open-source nature ensures transparency, community improvements, and long-term availability.
- Runs on Almost Any Hardware: From a full Windows laptop to a Raspberry Pi or Android tablet, OpenCPN is optimized to run on modest hardware commonly found on boats.
- Rich Plugin Ecosystem: Hundreds of community-developed plugins allow users to tailor the software to their specific navigation needs without extra cost.
- Offline-First Design: Works entirely offline once charts are loaded, making it reliable in remote ocean passages far from cellular or internet coverage.
Cons
- Steep Learning Curve: New users may find the interface and chart setup process less intuitive compared to commercial chartplotter hardware or apps.
- Dated User Interface: The UI design feels functional but aged when compared to modern commercial alternatives like Navionics or iSailor.
- Chart Acquisition Requires Extra Steps: Users must source and download charts separately, which can be a complex process for beginners unfamiliar with chart formats and licensing.
Frequently Asked Questions
Is OpenCPN really free?
Yes, OpenCPN is completely free to download and use. It is open-source software distributed under the GPL license, meaning there are no subscription fees or in-app purchases.
What platforms does OpenCPN support?
OpenCPN runs on Windows, macOS, Linux (including Raspberry Pi), and Android, making it compatible with a wide variety of devices used on boats.
Can I use OpenCPN without an internet connection?
Yes. OpenCPN is designed for offline use. Once you have downloaded your charts and loaded them into the application, no internet connection is required during navigation.
What chart formats does OpenCPN support?
OpenCPN supports a wide range of chart formats including S57/S63 ENC vector charts, BSB/KAP raster charts, CM93 charts, and more via plugins.
How do I extend OpenCPN with additional features?
OpenCPN has a plugin manager built into the application. You can browse, install, and manage community-developed plugins for features like AIS, weather, radar, tides, and route optimization directly from within the software.
