With the delivery of Leviathan, formerly known as project Y722, the Dutch shipyard Oceanco inaugurates a new phase in its industrial and cultural trajectory.
This 111-metre (363-foot) giga yacht, equipped with a diesel-electric propulsion system, represents a turning point in the way a yacht is conceived, built and experienced.
The project stems from the vision of its owner, Gabe Newell — founder of Valve Corporation and a leading figure in the tech and gaming world (Steam, Half-Life, Portal) — who, since the summer of 2025, is also a major shareholder of Oceanco.
Newell has infused the project with his own philosophy of collaboration and community, shaping every stage of development from design to construction and the onboard operational model. Leviathan is the outcome of a participatory process that brought together engineering, creative and operational expertise in a collective approach unprecedented in the giga-yacht sector.
The project is the result of joint work between Oceanco, its Design Team, Lateral Naval Architects, YTMC, Y.CO, Mark Berryman Design, the crew and an extensive network of co-makers and specialised suppliers.
Newell personally oversaw each stage, promoting an open and transparent method based on continuous exchange between engineers, designers and the yacht’s future operators.
“This iconic vessel began with a simple sketch, and the journey that brought us here has been extraordinary — a memorable human adventure that leaves us with a deep sense of humility and satisfaction,” said Patrick Casanova of Oceanco’s design team.
“We knew we were asking for unconventional solutions, and Oceanco embraced them with enthusiasm,” added Gabe Newell. “Together we designed a truly unique yacht that enhances the shipyard’s vocation for innovation, design and its ability to evolve construction processes.”
Designed to accommodate 26 guests and 37 crew members, Leviathan intentionally breaks down the traditional separation between guest and crew spaces, encouraging interaction and a sense of community on board.
Areas traditionally reserved solely for guests have been re-designed to welcome crew members as well — reflecting the owner’s belief that a yacht must first and foremost function as a community, where well-being and collaboration are central.
The bridge deck includes a shared gaming lounge with 15 workstations, two driving simulators and large relaxation areas, while the main saloon has been conceived as a communal dining hall for 54 people. Onboard amenities also include a basketball court, a recreational sundeck with jacuzzi, and a 3D-printing workshop for the autonomous production of spare components.
The interior style, developed by Mark Berryman Design, combines functionality and operational comfort. Crew areas feature oak and wenge finishes, while shared spaces use natural materials selected for durability and ease of maintenance, such as honed stone, shot-blasted steel and pure-wool carpeting.
Every design and material choice responds to a management-efficiency goal, reducing routine maintenance and allowing more time for high-value activities such as hospitality, research and training.
The deck is made of Bolidt synthetic material with a customised pattern inspired by the yacht’s exterior lines, designed to improve heat dissipation and minimise maintenance. Shot-blasted steel handrails and composite materials reduce polishing requirements, while the off-white exterior paintwork limits cleaning needs.
Architecturally, Leviathan adopts a distinctly contemporary language. Oceanco’s Design Team, led by Gilles Vernhet, created a forward-leaning silhouette with prismatic forms that express dynamism and fluidity, emphasised by a calibrated use of materials and colours.
During development, Oceanco and Lateral collaborated with MARIN for extensive hull-testing campaigns aimed at optimising stability and onboard comfort.
Leviathan features the latest evolution of the DE-Series hull, derived from the D-Series platform developed in 2010 and continuously refined over the years. Designed for large yachts operating at moderate speeds with pod propulsion, this hull form offers exceptional seakeeping both underway and at anchor.
Thanks to a variable-ballast system, a natural roll period above 12 seconds and a combined Quantum MagLift + XT Fins stabilisation package, the yacht provides superior comfort in all sea states.
Captain Alan Pike highlighted that during sea trials Leviathan stood out for its extremely low noise levels and total absence of vibration, even at maximum speed.
Propulsion is provided by two ABB DO980P Azipod units with five-blade propellers optimised through cavitation-tunnel tests. Noise and pressure-pulse reduction also extends to the structure, with reinforced steel foundations designed to minimise both high- and low-frequency vibrations.
The energy system integrates a 5.5 MWh battery pack that allows silent nighttime operations and improves overall efficiency through peak shaving, reducing consumption and engine cycles. The redundant electrical architecture is designed to ensure operational continuity and simplified maintenance.
Acoustic comfort received particular attention: full-scale tests were conducted to analyse noise transmission through HVAC ducts and glass integration, optimising materials and fastening systems to limit sound propagation into cabins.
The yacht is also equipped with a VFA Solutions air-filtration and monitoring system, a technology typically used in hospital and aerospace environments and adopted here for the first time on a superyacht of this size.
Leviathan joins the Inkfish fleet, the organisation founded by Newell to support scientific research and marine exploration.
Inkfish vessels — including the research ship R/V Dagon, equipped with a full-ocean-depth submersible — provide logistical and technological support for oceanographic and biological missions.
Onboard Leviathan are a scientific laboratory, a diving centre and a fully equipped medical bay located in the area traditionally dedicated to the beach club.
“Vessels have enormous potential to support scientific research,” says Gabe Newell. “It is about recognising that we are part of a wider community and ensuring that the yacht’s presence brings value to the places that host it.”
With Leviathan, Oceanco demonstrates how high-end yachtbuilding can evolve by integrating technical innovation, social responsibility and human well-being, laying the foundations for a new paradigm in the superyacht industry.
Key Specifications
Leviathan measures 111 metres (364 feet) with a beam of 17.8 metres (58 feet) and a gross tonnage of 4,970 GT.
The project was developed by Oceanco with Lateral Naval Architecture for naval engineering and Mark Berryman Design for the interiors.
Owner’s representatives are Y.CO and YTMC, while the build is entirely by Oceanco.
Propulsion is diesel-electric, with a top speed of 17.6 knots and a cruising speed of 13 knots.