"Swimming gave me a sort of joy, a sense of wellbeing so extreme that it became, at times, a sort of ecstasy.  I never knew anything so powerfully, so healthily euphorian and I was addicted to it, am still addicted, fretful when I cannot swim."    - Oliver Sacks

Swimsuits at Dawn documents a group of women who quietly swim, every day of the year, in the outdoor pools on Hampstead Heath in north London.