The Emerald Sea, by Richelle Mead

The third tale of the Glittering Court follows feisty Tamsin, the perfectionist with a secret, who is driven to be the best and make the best possible marriage. She made friends with Adelaide and Mira despite her competitiveness, which is the only clue that this rather unlikeable character from the first two books will turn out to be a natural leader with a strong moral compass. Tamsin’s story is even more full of unlikely adventures than those of her former bosom buddies – shipwreck, encounters with ‘savage’ tribes, confinement in a religious community, and just about every man she encounters falling for her. Unfortunately none of her suitors can offer the financial security she needs and so she returns to her focussed and driven self in pursuit of her goals when she finally gets to the city. This leads Tamsin to further unlikely misadventures, which miraculously reunite her with most of the major players from the earlier adventures and show her the right path to security and happiness.