Captain Mainsail, a name that inspires awe in the hearts and minds of ponies, and strikes fear into the minds of their enemies. However, it wasn't always that way. Mainsail started his naval career as a deckhand aboard a civilian transport vessel, a nobody. However, when the vessel is tasked with ferrying a certain royal family across the Eternal Strait, a series of events unfold that changed his life forever, and made him into a legend.

Gallant Topsail has dreamed of becoming the captain of a ship ever since he was a colt. When he became of age, he hastily enlisted in the Equestrian Royal Navy. He is currently stationed aboard one of the finest ships in the Equestrian fleet, the ERS(Equestrian Royal Ship) Resplendent. However, his dream of a captaincy is far from becoming reality, he is merely a cabin boy. Just as Gallant begins to loose hope in the possibility of attaining his ultimate goal, something happens that will change his life forever.