G-5, officially Marine "Grand Line" Fifth Branch (海軍G・L第5支部 Kaigun Gurando Rain Dai-Go Shibu?), is a Marine Base located in the New World, near the Red Line. It was first mentioned by Aokiji after the Battle of Marineford and according to him, it is full of problems. Smoker requested a transfer to this branch in order to "keep his targets close".
The headquarters of the G-5 location has several buildings left tattered or broken and slightly fixed from damages and appears to be left in ruins.
It is said that the Marines of this branch are insane, cruel, and merciless people who stick needles into pirates, feed them to sharks, or use them for campfire kindling. Although these actions are considered just rumors by some pirates, some were proven true when some of the Marines lit a captured pirate on fire and repeatedly stabbed another pirate while hanging him. They are known for not following the orders of their superiors, however, they seem to obey Smoker mostly by merit of intimidation and a mild respect for his great strength. Some members do not wear the full formal Marine uniform (if anything, they are overly-casual to the point of wearing slacks and a bucket for a hat) and act flirtatious toward their female superior, Captain Tashigi, although they do respect her as they tried to protect her from Law and took her with them to escape from Law's sphere and reassemble her body. They do appear to not be entirely fearless, as they were hesitant to follow the Straw Hat Pirates to Punk Hazard, which the Marines had declared that no one, pirates and Marines alike, should set foot on, for remnants of poisonous gas supposedly wreathed the island.
Regardless of their ruthless reputation, they seem to be easily frightened when they meet highly infamous people such as the Shichibukai Trafalgar Law. They too were helpless against the dangers of nature as seen when they panicked when a large piece of ice floated toward their ship. While initially hostile towards the Straw Hats, the members of Unit 01 willingly cooperated with them in order to defeat Caesar Clown and rescue the kidnapped children. During the ordeal in Caesar's facility, they even come to respect the Straw Hat crew. Even before the events on Punk Hazard, they appeared to have a great sense of comradeship, as they always tried to save their injured teammates during emergencies and even returned to the battle between Law and Smoker to save Tashigi. Despite these failures it can be said that they are quite strong as they are able to survive and operate in the merciless New World where most men are crushed by the climate and numerous pirates.
G-5 has about 300 personnel split into six divisions, with Smoker in command of Unit 01, and Yarisugi of Unit 06. The overall leader of the entire G-5 Base was Vergo, who acted in amiability in contrast to the majority of his subordinates, but was in truth a deep cover agent planted in the Marines by "Joker". His duplicity was discovered by Smoker and his second-in-command Tashigi, but they decided to keep it a secret for the sake of their subordinates, who admire him. He was defeated by Trafalgar Law and Smoker and left behind to die in the collapsing SAD production room. After Vergo's death, Smoker succeeded him as Base Commander. 
|G-5 Marine Sailors||
During the TimeskipEdit
Commodore Smoker and Ensign Tashigi transferred to the G-5 base sometime after the Battle of Marineford. Commodore Smoker was promoted to vice admiral and Ensign Tashigi was promoted to captain. This transfer left Vergo at unease, as he had to provide extra cautions to prevent his true identity from being discovered by the ever vigilant Smoker.
Dispatches about the kidnapping of children in the New World have been sent to the base, but were reported to newspapers as "accidents at sea" by Vergo, due to efforts to provide cover for Caesar Clown's unlawful scientific experiments on Punk Hazard.
Punk Hazard ArcEdit
Having been notified of the return of the Straw Hat Pirates, Smoker and Tashigi follow them to Punk Hazard. They first fight the Shichibukai Trafalgar Law and next got involved in the battle against Caesar Clown.
Later Vergo appears on the island  claiming to want to exterminate all of Smoker's division, but was stopped by Sanji and defeated by Smoker and Law. However, many personnel were petrified by the H2S that Caesar released into the building. After Caesar Clown, Vergo and Monet's defeat, Smoker states he contacted the base and they will be sending a ship to retrieve them.
Caribou's Kehihihihi in the New WorldEdit
During the events of the Punk Hazard Arc, Jinbe delivered Caribou to the base, where he was tied to a stake that was burning. To rescue him Coribou and the Caribou Pirates attacked the base, but were defeated by Yarisugi and his subordinates. However, Caribou managed to escape with his own ship and deserted his apprehended crew. The crew later escaped by stealing one of the base's ships.
Anime and Manga DifferencesEdit
The scenes of G-5 Marines torturing pirates were toned down in the anime for censorship reasons. The anime did not show them scorching their captive pirate, but simply holding their torches (and added spears) close to him in a menacing manner.
- The G-5 Marine Branch was formed on May 5th.