Pirate Captain

The title of Captain is the title given to the person in charge of a ship at sea.

Captains
Pirate Captains are the ones who are at the very head of a Pirate crew. Pirating captains also tend to be the mightiest members of their crew, and most of them tend to exploit their strength even over their own subordinates to ensure loyalty; though not necessarily, as anyone can attain the rank of captaincy out of pure leadership or even as a founding member. All major decisions are made by them.

Any naval officer below the rank of Taisa who commands a ship, is addressed as "captain" while aboard that ship, by naval custom. The ship's captain also may be referred to as the Skipper. A naval officer with the rank of captain traveling aboard a vessel he does not command is either never referred to by rank, or in some navies, is addressed as Commodore to avoid confusion with the ship's actual commander.

List of Pirate Captains

 * Gol D. Roger (Deceased; Jolly Roger Pirates)
 * Alvida (Formerly Alvida Pirates, Second captain of the Buggy Pirates)
 * Monkey D. Luffy (Straw Hat Pirates)
 * Shanks (Former apprentice of the Jolly Roger Pirates; Yonkou; Red-Haired Pirate Crew)
 * Buggy the Clown (Former apprentice of the Jolly Roger Pirates; Buggy Pirates)
 * Kuro (Black Cat Pirates before and after disguising as Kaya's butler 'Kurahadol')
 * Don Krieg (Admiral of the Don Krieg's Pirate Armada)
 * Arlong (Incarcerated; Former member of the Sunny Pirates; Arlong Pirates)
 * Edward Newgate (Yonkou; Whitebeard Pirates)
 * Marshall D. Teach (Former member of the Whitebeard Pirates; Blackbeard Pirates)
 * Macro (Former member of the Sunny Pirates; Macro Fishman Pirates)
 * Buubuu (Piggy Pirates)
 * Bellamy (Bellamy Pirates)
 * Montblanc Cricket (Former captain of an unnamed crew; Leader of the Saruyama Alliance)
 * Masira (Captain of one portion of the Saruyama Alliance)
 * Shoujou (Captain of one portion of the Saruyama Alliance)
 * Foxy (Foxy Pirates)
 * Mikazuki (Big Helmet Pirates)
 * Yorki (Deceased; First captain of the Rumbar Pirates)
 * Lola (Rolling Pirates)
 * Capone Bege (Firetank Pirates)
 * Jewelry Bonney (Bonney Pirates)
 * Eustass Kid (Kid Pirates)
 * Scratchmen Apoo (On Air Pirates)
 * Basil Hawkins (Hawkins Pirates)
 * Urouge (Fallen Monk Pirates)
 * X. Drake (Former Marine Rear Admiral; Drake Pirates)
 * Trafalgar Law (Heart Pirates)
 * Boa Hancock (Former slave; Shichibukai and empress of Amazon Lily; Kuja Pirates)
 * Fisher Tiger (Deceased; First captain of the Sunny Pirates)

Former Pirate Captains

 * Jango (Second captain of the Black Cat Pirates; Currently a member of the Marines)
 * Jinbei (Second captain of the Sunny Pirates; Currently on the verge of losing his title as Shichibukai)
 * Wapol (Wapol Pirates; Former king of Drum Kingdom (now called 'Sakura Kingdom'); Currently a CEO of his own toy company)
 * Kiba (Fanged Toad Pirates; Currently a member of the Foxy Pirates)
 * Brook (Second captain of the Rumbar Pirates; Currently a member of the Straw Hat Pirates)
 * Gecko Moria (Unnamed crew was massacred (implied to be by Kaidou of the Yonkou); Currently a member of the Shichibukai)
 * Dias (Acumate Pirates; Former slave; Currently in custody of the Marines)
 * Jean Bart (Unnamed crew; Currently a member of the Heart Pirates)
 * Portgas D. Ace (Spade Pirates; Currently Second-Division Commander of the Whitebeard Pirates)

Marine Captains

 * Morgan (Stripped of rank, current whereabouts unknown)
 * Nezumi
 * Hina
 * Moor (Anime only)
 * T-Bone
 * Very Good
 * Shuu
 * Sharinguru
 * Attachan (Photography branch captain)
 * Sentoumaru (Science unit captain)

Trivia

 * A Marine Captain (大佐) is a rank junior to that of a Commodore. It is second most seen rank in One Piece to date, having 8 representatives and being second only to that of Vice Admiral in terms of appearance. The number of seen captains MAY have surpassed the number of seen vice admirals, during the Enies Lobby assault on the Bridge of Hesitation, where no one below the rank of captain was to attack, we have not seen many of them more then once and only from from afar, except three (Sharingu, Shuu, Very Good) however, these were never specifically referred to as "captains", until being dubbed as such by Oda in the SBS of volume 47.  Even then "captain" is just the equivalent rank in English speaking armies (America and Brittish) to the Japanese given for their rank.
 * Supernova, Eustass Kid has a nickname of "Captain".