The Light Between Oceans by M.L. Stedman
A lighthouse keeper along the southwestern coast of Australia, between two oceans (the Indian Ocean and the Great Southern Ocean), builds a life for himself in solitude after fighting in WWI. He meets the love of his life, they marry and move to the island. The book opens when a small boat washes up on their shores. The boat is carrying a dead man and a living baby. The story and the intrigue start there... and it's a good read! You'll want to know what happens to all the characters in this book.
I argued with myself: what would I do? What should they do? And at times I worried about turning a page to see what's about to happen.
You'll be glad you read this well-done book.