The Question and Answer section for The Awakening is a great resource to ask questions, find answers, and discuss the novel.
Sorry, my page numbers may not be the same as yours.
I think this is part of the nonconformist theme of the book. Edna embarks on a path of emotional, intellectual, and sexual awakening after spending a very pleasant summer with her young admirer, Robert Lebrun. In trying to gain a sense of herself...
The sea is wild cold and limitless: Edna plunged and swam about with an abandon that thrilled and invigorated her.