Islet in Skedviken — Stockholm County County, Norrtälje Municipality.

Skedviken has a digitised depth map based on real soundings. It shows the depths across the whole lake, including the water around Söderbyholmen.
View the depth mapWhere does it shelve off around Söderbyholmen?
You can see it in Huggtabell's digital depth map for Skedviken — real soundings, tap anywhere for the depth, and follow your GPS position out on the water. Solunar, weather and water temperature are included.