Nameless Captain
The narrator of the story, this is a young man who only a fortnight before the story begins receives his first command of a ship. Because he has been on the ship only two weeks, at the beginning of the novel he feels like he is not only a "stranger to the ship" but also a "stranger to himself." Deeply introspective, he is one of only two characters in the book that is fully exposed throughout Conrad's story and the story revolves around his personal inadequacies and the resolution of those same inadequacies. Once he rescues Leggatt, an escaped criminal, he feels a deep bond with the man, like he is his "secret self," hence the title of the book. By hiding him and assisting him to escape, the captain not only regains control of his own life, but he overcomes his personal inadequacies, wins the respect of his crew, and most importantly, comes to know himself much better.
Leggatt
An escaped criminal, it is his presence on the nameless ship that brings crisis to the captain and his ship. Originally, a first mate on the nearby Sephora, during a storm Leggatt, in a just rage, murdered an inferior, but in the process, saved the ship. Unappreciated, he is locked up for weeks before he escapes the ship and swims to nearby ship on which the captain resides. Like the captain, he is a young man and went to the same boy's prep school as his "secret self." While onboard the ship, Leggatt's presence is not revealed to anyone but the cabin, because the man hides in the captain's quarters, particularly in his bathroom, wearing a gray sleeping suit that is identical to the captain. Coincidently, the man is the same size and build as the captain, as well as having the same color of hair. After four days on the ship, Leggatt realizes that he cannot go back to society (he is willing to accept the consequences of his actions) and so, with the captain help, he is smuggled off the ship, never to be heard of again.
Captain Archbold
The captain of the Sephora, many critics believe that he is the true villain of The Secret Sharer. With red whiskers, he is nervous and scared of all that is on his ship, including the first mate, Leggatt, and even his wife. Harsh and unwilling to compromise or admit that he is wrong regarding his stance towards Leggatt, he is a foil to both the captain and Leggatt as someone who is strictly law obeying. During his conversation with the captain, he gives off an air of fussy distraction, and in his most authoritative act sticks out his tongue to imitate the death mask of Leggatt's victim. Archbold's solemnity is contrasted with the playfulness of the captain, who fakes being deaf and happily leads his guest on a futile search of the ship.
The Chief Mate
Throughout the narrative, the captain refers to this character as "terrible whiskers," "frightful whiskers," and "terrific whiskers." The captain considers every occurrence on the ship, trying to figure out they why and how of things. Most identifiable, he is concerned with why a scorpion chose his cabin to drown in an inkwell.
The Second Mate
The only man on the ship who is younger than the captain, he is extremely critical and looks down on the captain.
The Steward
His main function is plot, as the character who comes in closest contact with the captain, he is most likely to discover the secret of Leggatt. Primarily because of this function, the captain becomes rude and surly towards him throughout the course of the narrative.
