The person who is associated with bathing in the sea with Edna repeatedly in the first few chapters is of course Robert, and this is ironic because of the symbolism of the sea in this novel and how it is used to symbolise liberation and escape from the confines of society and the roles that society give humans. Note how the sea is introduced in Chapter Six, which comes just after Edna has changed her mind and given in to Robert's entreaties to go bathing with him:
The voice of the sea is seductive; never ceasing, whispering, clamouring, murmering, inviting the soul to wander for a spell in abysses of solitude; to lose itself in mazes of inward contemplation.
The sea is associated very strongly with both sensuality but also introspection which causes Edna to question the role she has been given in society. It is therefore significant that it is Robert who goes bathing with Edna because it is Robert who becomes the focus of Edna's rejection of her married life and the way that society expects her to act. Robert through the symbolic act of swimming gives Edna a taste of the liberation that she so eagerly craves in life when they go swimming together. In addition, this act of swimming together also foreshadows the tragic ending, when Edna realises she "had gone out too far." Literally and metaphorically, Edna has sought too much freedom, and is unable to get back safely, and has only one option left to her: suicide.