The Grand Banks Cafe by Georges Simenon (1938) Gallimard 

Maigret and his wife take a holiday at Fécamp, Normandy.  While there, he looks into a murder of a ship’s captain.  Like all Maigret mysteries, his approach is to take in the scene and the people involved.  Once he knows all that, he follows his instinct and uncovers the motives of people involved, then life goes on.

 

I could only find the original French through the Internet Archive.  You can also get it in English from Penguin.