Syvänne

Syvänne is a Finnish map-based chartplotter delivered as a Chrome extension for fishermen and water enthusiasts. It uses official Finnish map data to display sea and lake maps, show your location, speed, and direction, and compute travel time. You can plan routes on the map and view hotspots where productive fishing spots are likely, based on base shapes.

Markers can be left on the map and distances measured easily. The app keeps your privacy—markers are not shared with outsiders. It runs in the background, so you can use other apps while boating. Remember to carry official Traficom paper maps as the primary navigation tool and navigate safely; Syvänne is a supplementary, free-to-try chartplotter with paid options after the trial ends.