My goodness. I'm surprised no one has beaten me to the punch on this.
The premise is fairly simple: A World War I era destroyer, Walker, engages with a Japanese battle cruiser (along with the accompanying other vessels) in the early days of World War II. As they are being pursued, pummeled and looking death in the face, the Walker's captain orders the ship into a squall in a desperate attempt to escape.
That attempt succeeded a little too well. The Walker and its crew and hangers on from the evacuation of Java find themselves somewhere else. The ocean is full of fish the size of tuna that act like pirahna, plus sea monsters. As they gather information, they find dinosaurs grazing where a coaling station would be as well as small predators that are aggressive as all get out.
Further exploration leads them into contact with the ocean going Lemurians - sentient descendants of Lemurs and the discovery of their problems - namely, the existence of dinosaurian race called the Grik that will pursue the Lemurians to extermination.
I know basically recapitulated the cover blurb for the book, so let's get into the likes and dislikes.
Like: Interesting world building, early 20th century attitudes of the characters, view of WWI destroyer from the deck and the con.
Dislikes: Characters are a bit stiff, things take place too quickly for my liking, things also go too well for the human protagonists.
Overall, I liked it. I'd like to see more of the world and will check out Crusade the next book in the series. It reminds me of my much beloved World of Kong.
I'd suggest it as a fast fun read for fans of books like A Connecticut Yankee in King Arthur's Court, Islands in the Sea of Time and similar series as well as fans of military fiction.