The Land That Time Forgot

When a German U-boat sinks his ship, Bowen Tyler ends up in the Atlantic with his Airedale, Nobs, and soon he is helping to capture the very submarine that attacked him. His family's yard built it. Now Bowen, a rescued young woman named Lys La Rue, a handful of British sailors and the captured German crew share one hull, one fuel supply and no trust at all.

Sabotage drives them far off course, into southern waters no chart describes, until a wall of cliffs rises out of the sea. This is Caprona. Through an underground river they reach Caspak, a warm, forgotten land where dinosaurs hunt in the forests and men of every stage of evolution live in the hills.