Luotsi - Marine Navigation is a free and ad-free application designed specifically for navigating Finnish waters. It provides users with real-time GPS positioning on vector charts, enabling smooth zooming and course-up views. The app allows users to log their trips, tracking distance, duration, weather conditions, top speed, and average speed. Additionally, it features a measurement tool for calculating distance and bearing between points, as well as route planning capabilities. Users can save waypoints and access weather forecasts at specific locations, including wind and weather data for the hours ahead.

The app also includes live AIS functionality to view the positions of other vessels, data on pump-out stations, property boundaries, and a dynamic wind map. Users can download specific areas for offline use and export GPX files for backup. Importantly, Luotsi prioritizes user privacy, ensuring that location data remains on the device without any tracking or ads. While it harnesses open data for its features, users are advised to use it alongside official nautical charts and equipment.