As is the case in any great novel, The Shipping News employs a number of literary devices. Proulx uses similes to great effect to convey her purpose.
A great example can be found early on in the story when Quoyle recalls how his father viewed his failures.
The father saw other failures multiply like an explosion of virulent cells.
This comparison uses the word "like," which makes it a simile. The simile compares Quoyle's failings to the rapid spread of a virus. This conveys Proulx's purpose by expressing just how undesirable Quoyle's traits are to his father.
Another memorable simile comes much later in the story when Quoyle is racing against time to get back to Killick-Claw and takes his boat to sea in water far rougher than he immediately realizes. The crests of the waves are described as being "like cruel smiles," and the simile serves to help create an image of a tossing, churning ocean. This helps to fulfill Proulx's purpose of describing a dangerous situation.
Similes can also use the word "as" to make their comparison. A touching simile is used to describe the way the children rush at Quoyle. They are described as holding him "as a falling man clutches the window ledge." This literary device is used to create the feeling of the children's fear of being separated from Quoyle.
Similes are used for various purposes, and in many situations they can help to bring a story to life or create vivid images.