The slink of summer goes up against working structure. Hint: wear lightweight outerwear as a dress with a maillot beneath and slip under the waves in a flash. Lee Mathews trench coat, $1,450, and swimsuit, $299. Chanel Code Coco steel and ceramic watch set with diamonds, $15,850, from the Chanel boutiques. Beauty note: Chanel Le Vernis Nail Colour in Beige Beige.