LakeMap · Support

LakeMap Support

Answers to common questions and a direct line to the development team.

Frequently asked questions

Does LakeMap work without internet?: Yes. All charts ship inside the app and work offline. A connection is only used to refresh the current lake level and the weather forecast — both are cached and shown with their age.
Why are some areas shown in violet?: Violet means there is no depth data for that area. LakeMap deliberately shows such zones as a hazard — on some lakes it is precisely the shallow shore that is missing (e.g. everything shallower than about 5 m on Lake Zurich). Treat violet areas as unknown shallow water.
Why does the depth differ from my paper chart?: Paper charts show depths against a fixed chart datum. LakeMap computes with the current water level from the Swiss federal gauges (FOEN), so the depth shown is today's depth. Two lakes have no gauge (Lungernsee, Rotsee); they use a nominal level, labelled as such, which you can override manually.
Which lakes are included?: Lake Zurich, Lake Constance, Lake Lucerne, Lake Thun, Lake Brienz, Lake Biel, Lake Neuchâtel, Lake Murten, Lake Geneva, Walensee, Lake Zug, Lago Maggiore, Hallwilersee, Ägerisee, Baldeggersee, Sempachersee, Sarnersee, Lac de Joux, Silsersee, Silvaplanersee, Lungernsee, and Rotsee — every lake swisstopo publishes a survey for.
Can I use LakeMap for navigation?: LakeMap is an information tool, not an official navigational aid. Official charts and the shore storm-warning lights remain authoritative.
How do I delete my data?: LakeMap has no account — tracks, settings, and position live only on your device and are removed when you delete the app.