Map of the Channel Islands. 
Note: This image is a simplified version of Image:Channel Islands.svg. It is to serve as a thumbnail in the article about Sark and shall also show the position of the island there.
Own work
Hannes2 (me),  using PD Maps (see this and that) from the CIA World Fact Book for the shapes of the Islands and a PD NASA satellite image (see this) for their position and the shape of the French Coast.