Embedded Onboard System for a Yacht

This bachelor thesis addresses the need for an affordable and customizable onboard navigation instrument for small recreational yachts that combines basic GNSS navigation, voyage logging, and safety workflows in a purpose-built interface. The theoretical part introduces GNSS positioning, marine navigation data exchange, existing chartplotter and software alternatives, and user-interface constraints in a cockpit environment. The practical part evaluates this approach through custom-built software called Helm~OS. It runs on a functional Raspberry~Pi~5-based prototype with a Waveshare LC76G GNSS module, touchscreen display, DC/DC power supply, and custom PETG enclosure. The application is implemented natively in Qt. The software receives NMEA~0183 data over UART, validates and parses navigation, satellite, time, and accuracy information. It displays position, speed over ground, course over ground, and GNSS status, and records voyage data in an electronic logbook with CSV and GPX export. It also implements two safety workflows: Man Overboard and anchor alarm. The system was verified by automated unit tests, processing of a synthetic NMEA replay stream, and an integrated live-GNSS field test on a vessel. The result meets the main functional goals at prototype level, while remaining limited by cold-start time, brightness and viewing angles of the consumer display, touch-control limitations in wet conditions, and the absence of a certified ingress-protection rating.