Marines

First Appearance: Chapter 3; Episode 1

About
The Marines (海軍) are the World Government's military sea force. It is present in all the seas around the world, although they maintain only a slight military presence in the four Blues by establishing Branch Offices. The focus of the bulk of its assets on are on the far more dangerous Grand Line.

Duties
The duty of the Marines is to maintain a law and order throughout the world and impose the will and might of the World Government. They are therefore considered the key strategic development force in the World Government and are expected to obey its orders at will. Sometimes these orders are questionable, however they are expected to carry them out regardless of opinion. Amongst their duties is awarding bounty hunters the bounties on the heads of a criminal. They tolerate bounty hunters as a method of making their job easier but are not unknown to go out bounty hunting themselves. Apprehended criminals who are brought in alive are handed over to be made an example of, the Marines are left to ensuring the exportation of these criminals to prison and/or to their execution.

Marines often work in pairs with one superior officer and a second in command or subordinate who is of slightly low rank. These partnerships may remain even during promotions with both pairs advancing in rank together. In the pair the higher ranked officer will give the orders to the men under their command, while the other acts an adviser or information gatherer while ensuring their partners command is undertaken by the men.

Higher ranked Marines (Admirals and Fleet Admiral) are expected to be on call to led the Marine forces into war. This may take form of comprehending many criminals at once, protecting the World Nobles or calling a Buster Call at tackle a situation. Vice Admirals are the ones who serve on the ships that the Admirals call out and are tasked with carrying out the Admirals orders exactly.

The main purpose of the Marines remain footed in the idea of bringing Justice to any criminal. They use Justice as their constituted policy to manage a world that is made entirely of one ocean much easier. However, the main problem within the Marines is the approach to Justice. They are generally divided between those who support Moral Justice and those who support Absolute Justice with the latter being the code of conduct for the Marines as a rule. Nevertheless, there is little worry from the higher ranked Marines as to how the Justice is carried out so long as it is, leading those who truly support absolute Justice to make unjustified actions in carrying out their duties.

The final duty the Marines have to to aid the Shichibukai, or allow the Shichibukai to aid them, in maintaining the balance between both sides forces and the Yonkou.

Rank System
The system of military rank in place for the Marines is fairly straightforward, where each rank is clearly delineated.

Officers and recruits present at Marine Headquarters are considered "Super-elites". All ranks present from "Lieutenant" above are usually trained here, exceptions being those in command of other Marine bases which includes Axe-Hand Morgan and Nezumi.

Rank Insignia
The Marines do not have a system of rank insignia per se. There is significant variation in the kind of uniform worn by officers, with many opting to wear a variety of dress showcasing their own eccentric style. Marines are also allowed to wield whatever weapon they are most comfortable with, no matter how unusual it is. They are even free to fight bare-handed. However, as a general rule set down by the author, uniform guidelines are as follows:
 * Upon first entering the Marines, new recruits are given the standard uniform, consisting of a white short-sleeved shirt emblazoned with the Marine emblem, a simplified seagull with "MARINE" underneath it, on the back; a blue neckerchief; dark blue trousers; and a baseball cap with "MARINE" across the front. All officers at the rank of Seaman (一等兵 Ittōhei) and below wear this. The quasi-rank of "Zatsuyō" (雑用 Zatsuyō) adds the kanji 雑 Zatsu ("various" or "odds and ends") to the sleeves, and to the Marine emblem on the back.
 * Once an officer has reached the rank of Petty Officer (伍長 Gochō), he or she can choose from a number of different uniforms, including his or her personal clothes. Only those who really want to appear "sailor-like" will stay with a more traditional uniform.
 * Sailors at the rank of Warrant Officer (准尉 Jun'i) and above are allowed to wear the coat with "Justice" (正義 Seigi) on the back. This coat tends to be worn like a cape, draped over the shoulders with the arms not in the sleeves.
 * For the rank of Lieutenant-Commander (少佐 Shōsa) and above, a suit worn underneath the "Justice" coat is the preferred attire.

There are, of course, exceptions: Jango and Fullbody wear their own clothes with the "MARINE" hat, despite holding the rank of "Seaman Recruit" (三等兵 Santōhei). This may have something to do with the exceptional circumstances by which both of these men were brought into their present situation, or it may simply be lenience on the part of their Captain, Hina.

Commissioned Marine Officers

 * Fleet Admiral (元帥)
 * Head of the Marines
 * Admiral (大将)
 * Governors-General of the Marines; only three such positions
 * Vice Admiral (中将)
 * Rear Admiral (少将)
 * Commodore (准将)
 * Captain (大佐)
 * Commander (中佐)
 * Lieutenant Commander (少佐)
 * Lieutenant (大尉)
 * Lieutenant Junior Grade (中尉)
 * Ensign (少尉)

Infantry and Sailor Division

 * Chief Warrant Officer
 * Master Chief Petty Officer
 * Chief Petty Officer
 * Petty Officer
 * Seaman
 * Seaman Apprentice
 * Seaman Recruit
 * Apprentice
 * Chore Boy

History
Exactly how long the Marines have been around is unknown and how they were created.

The oldest known date of their existence was 1472 AOS where Oimo and Karsee were captured by the Marines and was tricked in guarding Enies Lobby in hoping to free Dorry and Broggy whom they thought had been arrested.

In 1500 AOS, Garp was known as the legendary Marine who cornered Roger many times. After the Execution of Roger, the Marines and the Marine Judges went to Water 7 to judge and later execute Tom for supporting him in his pirate deeds by constructing Roger's ship the Oro Jackson.

In 1502 AOS, a platoon of Marines, including five Vice Admirals, were sent to Ohara for the execution of a Buster Call regarding the research of lost history that annihilated the island. Three of the most notable who took part included future admirals Kuzan and Sakazuki as well as Jaguar D. Saul, who sacrificed his life in protection of the island.

Filler Marines
Below is a list of marines that are found only in the anime.
 * Daddy Masterson is a bounty hunter and former marine sniper.
 * Lieutenant Drake is a Marine officer stationed in G-8 Marine Base, under Vice Admiral Johnathan's command.
 * General Gasparde appears in the fourth movie. He is a former Marine who ate the Ame Ame no Mi, giving him the ability to turn any part of his body into candy syrup
 * Governor is the antagonist of the third TV special. Governor is a corrupt marine lieutenant who once served under Randolph during his time in the marines.
 * Isoka is a female marine of significant rank in the anime only Rainbow Mist arc.
 * Jessica is the head chef at G-8 and the wife of Commander Jonathan.
 * Commander Johnathan is an anime-only Vice Admiral stationed in G-8. He tends to spend the night fishing and is often seen relaxing and meditating, but despite this he is a brilliant strategist.¨
 * Dr. Kobato is a pediatrician at G-8 that faints at the sight of blood, though during the events of the G8 Arc all of the other doctors are gone, making it so that she has to handle the trauma patients.
 * The Marley Brothers are a pair of cooks from Mariejoa that came to G-8 in order to start cooking there.
 * Mekao is an old mechanic and shipwright from G-8 who shows great pride in his work. He becomes friends with Usopp and later helps the Straw Hat Pirates escape the base.
 * Minchi is a marine in the Goat Island filler arc. He is a subordinate of Captain Moor.
 * Captain Moor is a marine appearing in Goat Island Arc.
 * Commodore Nelson Royale is an extremely obese anime-only Marine officer on the East Blue, who seeks the Thousand Year Dragon, Ryūji, for his own selfish purposes.
 * Randolph is a character that appears in the third TV special. Randolph is an ex-marine turned actor known for his excellent acting ability.
 * Rapanui is a high ranking marine in the Rainbow Mist filler arc.
 * Shepherd is a commander from Marine Headquarters that comes to G-8 in order to inspect it.
 * Tajiyo is a boy the Straw Hats meet in one of the episodes in the Post-Arabasta Arc. He's a young Marine cook.
 * Touma is a marine swordsman in the 5th One Piece Movie.
 * For Marines with stated or implied high rank or plot importance see Unnamed Filler Marines

Translation and Dub Issues
Although the literal roman characters "Marine" are displayed prominently throughout the manga on the hats and uniforms of officers and at military installations, the Japanese word that is used is "海軍" (かいぐん) "kaigun", which translates most closely to "Navy".

One of the reasons that Navy is the traditional English translation of the word "kaigun" is the close association that the Imperial Japanese Navy had with the British to the extent that bridge commands in the INS were even issued in English until shortly before WWII. As a result, Viz as well as 4kids decided to translate it as "Navy". While Viz alters the various "kaigun" kanji to read Navy in English while leaving the word Marine alone on various equipment and personnel 4Kids, on the other hand took a different approach. 4Kids opted to erase kanji and to change all instances where the word "Marine" appears in the artwork to read "Navy".

In English, to call the Navy the "Marines" or the "Marine Corps" can be considered a mistake, because Marines (in the English sense of the word) only make up a portion of the Navy's forces. For example, in the American Army the word "Marine" is used to describe an army unit who is deployable on land or at sea, while a strictly seafaring force is called a Navy. Evidence from the series (specifically, the author's frequent use of vocabulary from a variety of mainland European languages) suggests that the use of "Marine" in the Navy's emblem may come from French or German. In both these language "Marine" has the same meaning as the English word "Navy".

Nevertheless, English speaking fans of the series generally accept either term, though some who are fans of the Japanese version (but do not actually speak Japanese) have been known to criticize the use of the word "Navy,". This is normally either as a knee-jerk reaction against the 4Kids dub of the Anime (which uses the term) or out of unawareness that the word "Navy" is a more proper translation of the term "Kaigun". In the end, it is important to remember while Navy or Marines can be used as the correct term for the group, using "Marine" as a direct English translation of the Japanese is incorrect.