Like many officers in the British fleet, Aubrey spent much of his life raised on the sea, joining the navy very early: he was on the books at the age of nine and at sea when he was twelve. While a midshipman aboard HMS "Resolution" commanded by a friend of General Aubrey's, Captain Douglas, Jack was turned before the mast for hiding a girl aboard the ship. He spent six months as a common seaman before being re-rated as a midshipman. This was when Lord Keith was still Captain Elphinstone, therefore pre-1797.