Final answer:
In the Percy Jackson book series, Percy, Annabeth, and Tyson board the Argo II, a magical Greek trireme.
Step-by-step explanation:
Percy, Annabeth, and Tyson board the Argo II boat. The Argo II is a magical Greek trireme created by the children of Hephaestus from Camp Half-Blood. It is described as a bronze warship with an iron-plated ram and a dragon figurehead. The boat is used by the characters in the Percy Jackson and the Olympians and The Heroes of Olympus book series written by Rick Riordan.