Suit

While Herself heartily dislikes putting on a bathing suit, she would make an exception for this one, from ModCloth.  Retro! Supportive! Not excessively revealing! And best of all, science-y.  Excellent.

You can find it here: 

http://www.modcloth.com/shop/twopiece-swimwear/you-ve-got-chemistry-swimsuit-top-in-bustier