Argo II

The Argo II is a flying Greek trireme built by the Hephaestus' cabin for the journey of the seven demigods of the second Great Prophecy to Greece. It is currently manned by Leo Valdez, Piper McLean, Jason Grace, Frank Zhang, Hazel Levesque, Nico di Angelo, and Gleeson Hedge (due to the temporary loss of Percy Jackson, and Annabeth Chase).

History
During the Demigod Civil War, Bunker 9 was used as a command post for the Hephaestus cabin. An unknown camper designed blueprints for a flying ship that may have been related to a prophecy, as there is a note stating "prophecy? Unclear. flight?" While the designer was never known, the name of the blueprints led to revealing the name of the ship—Argo II. The creator never made the ship and eventually the bunker was abandoned. Decades later, Leo had a dream about the Argo II, made out of flames, when he was two while he was still under the care of Tia Callida. When he was five, he drew a picture of a flying ship in crayon. The ship was decorated with flames and its masthead was the head of the metal dragon, Festus. Leo, however, lost the drawing in the wind though was much later returned to him by Aeolus.

The Lost Hero
Years later, Leo discovers he is a demigod and is sent on a quest to rescue Hera, Queen of the Gods. Before they leave, Leo discovers Bunker 9 after repairing the bronze dragon that he names Festus. He sees the blueprints for the large ship he drew when he was younger, but focuses on adding a pair of wings to Festus. While visiting Aeolus to ask for help, Aeolus returns Leo's drawing of the Argo II (not named at the time) to him claiming that everything lost in the wind finds its' way to him. Leo takes the picture and puts it in his pocket without showing Jason or Piper.

After the quest is completed, Leo shows Bunker 9 to the rest of Cabin Nine, including the Argo II blueprints. He shows them the picture of the ship he drew when he was five, and feels that the ship is tied with his destiny and says he is going to build it, with the head of the recently destroyed Festus as the mast head. When Leo pulls out his crayon drawing, everyone compares it, and they all find that the drawing and blueprint are the same. Then, he and the Hephaestus cabin start to build it, to sail to Camp Jupiter.

The Son of Neptune
Percy has dream visions of Jason, Piper, and Leo finishing the ship and welding the head of Festus to the mast. However, the ship's samophlange breaks and Leo says it could take a few days to fix. At the end of the book, the ship appears on the horizon and Percy gathers Camp Jupiter to meet them in the Forum after he is elected Praetor.

The Mark of Athena
The Argo II arrives at Camp Jupiter and attracts the attention of the demigods and the legacies at camp. Terminus intercepts them by appearing on their ship, telling them that they cannot proceed past his Pomeranian Line and that they cannot land, so they convince him to let the ship float over New Rome instead. Later an Eidolon took control of Leo and made hime fire on new rome

Later, Leo plans on using Archimedes' spheres and other discoveries to upgrade the ship.

Appearance
The ship is a magical trireme with one sail and a few banks of oars. It's 200 feet long (61 meters) with a bronze hull, and a flaming dragon head at the top of the mast. The ships main weapons are two repeating crossbows that could fire explosive bolts powerful enough to blast through concrete. It has oars that can change into spears if needed and the mast head is able to breath fire. It is unknown exactly how the ship is able to fly, but it is able to stop in mid-air and has a landing gear system so it can dock on dry land. Both Leo Valdez and Jake Mason describe it as "A spankin hot war machine," though Jake says this as he examines the old blueprint for the ship.

The controls consist of a keyboard monitor, aviation controls of a leer jet, dubstep soundboard, and Wii remotes and sensor which control different aspects of the ship. The Argo II has cabins for each of the seven and Gleeson Hedge. The mess hall is styled like Camp Half-Blood, which makes Leo feel bad, knowing that Frank Zhang and Hazel Levesque had never gone to Camp Half-Blood. There are also stables for the pegasi, however they are not very useful, as pegasi like to roam around.