What happens when you combine 3D printing with the high-stakes world of marine engineering? You get a sea scooter that is born, not assembled. In this session, we explore the design and fabrication of a fully functional underwater vehicle featuring a unique constraint: a single-piece, hermetically sealed hull with zero holes. No drive shafts, no charging ports, and no external switches. This talk dives into the 500-hour journey of overcoming the physics of water pressure and the logistics of "mid-print assembly." We will discuss the engineering of a contactless magnetic gear drive system, the integration of inductive charging through a plastic hull, and the heart-stopping moment of dropping a fully powered drive system into a 3D printer mid-job. Most waterproof electronics rely on O-rings, gaskets, and seals—all of which are common points of failure. This project sought to eliminate those failures by creating a "monolithic" hull.