Unlike in US, for example, public nudity is perfectly normal in Finland. No one will stare at you, and no one is embarrassed, if you are nude. In the summertime, men and women will always be naked when swimming or taking sunbaths, in public beaches.
Finns are accustomed to being nude in presence of others, because of the thousands of years tradition of sauna . Remember that no one ever wears any clothes in sauna , because the sauna spirit would be angered otherwise.