To Believe A Buccaneer a.k.a. Beautiful Disaster by Heather C. Myers
This is an intriguing and entertaining story, but there's not much romance to it. Johnny, a pirate who appeared from the 18th century, is just like Capt. Jack Sparrow, charming, amusing, bold, but when he meets Izzy, he also becomes caring and protective. Izzy is vulnerable, insecure and stubborn. Johnny pops into her life while she's waiting at home to surprise her boyfriend. Unfortunately the surprise is on her when he shows up with another woman. She throws him out and spends the next 2 months teaching Johnny about the 21st century. The night of her graduation they find themselves back in his time, because he needs to lead his fellow pirates in the war against the British Navy, but first he had to learn to not be selfish. It's a very entertaining story.