Lyric discussion by artyrant 

Cover art for Swimming lyrics by Florence + the Machine

I think this song is about Loosing yourself, weather it be in the world or in some activity, and hearing something that reminds you of who you are and what you used to be. It brings you back to who you really are. Because as you were drowning you were loosing yourself. While your swimming, your perfectly comfortable with who you are.

My Interpretation