Harry Heron Into the Unknown (The Harry Heron Series Book 1) by Patrick G. Cox

The start of the Harry Heron Series. A freak accident on board the HMS Spartan during a sea battle with the French navy in 1804 catapults Midshipman Harry Heron and his shipmates Ferghal O’Connor and Danny Gunn four hundred years into the future, landing them on the NECS Vanguard, flagship of the World Treaty Organisation Fleet. While Captain Blackwood and Major Heron sort out the mystery and determine whether the young men are alive or dead, Harry and his friends are faced with the challenge of learning new roles aboard a spaceship. Just as they have found their footing, they are called upon to assist the Fleet in a rescue mission on the planet Pangaea, giving them the opportunity to prove that their unique skills from the past are still very relevant in the far distant future.