Fleetzero, Thoma-Sea, and Glosten Announce Collaboration to Deliver Long-Duration Autonomous Vessels

The collaboration pairs Fleetzero's marine power and autonomy stack with Thoma-Sea's shipbuilding scale and Glosten's vessel design and marine engineering expertise, advancing autonomous vessel solutions for commercial and defense missions.

HOUSTON, June 2, 2026 /PRNewswire/ -- Fleetzero, a U.S.-based developer of marine technology, today announced a collaboration with Thoma-Sea Marine Constructors, a leading U.S. shipbuilder, and Glosten, a Seattle-based global naval architecture and marine engineering firm, to accelerate the development and deployment of integrated autonomous vessel solutions for commercial maritime, government, and defense customers.

The partnership brings together Fleetzero's Leviathan™ Battery Energy Storage System, propulsion technologies, and autonomy stack, with Thoma-Sea's domestic shipbuilding capacity and Glosten's vessel design expertise. The three companies are developing a tightly integrated autonomous diesel-electric vessel engineered for use in contested waters, persistent operations, and supply delivery with minimal radar cross-section. Its angular design draws inspiration from low-profile and stealth vessels in military use today, and elevates the propulsion technology for long-range, low-signature missions.

The combined capability has been refined through demonstrations and engineering work with organizations across the maritime sector, and is engineered to address requirements outlined in areas of interest for the Defense Innovation Unit (DIU) and other Department of War stakeholders. The integrated platform showcases how electrified propulsion paired with autonomous vessel control enhances operational effectiveness across contested littoral and blue-water environments, while delivering the supply chain resilience that commercial and government customers require.

The collaboration aligns with Department of War, MARAD, and Coast Guard priorities, including the Modular Open Systems Approach (MOSA). The combined platform addresses a wide range of operational needs, including:

• Autonomous and remotely operated cargo operations
• Persistent ISR, patrol, and contested logistics missions
• Electrified harbor craft, tugs, and coastal vessels
• Improved operator safety
• Domestic-content, Jones Act, and Buy American compliance

ELECTRIFYING AND AUTOMATING THE MARITIME FLEET

As the U.S. Department of War, MARAD, and allied maritime forces accelerate adoption of autonomous and remotely crewed surface vessels, the ability to deliver electrified, autonomy-ready hulls from domestic shipyards is becoming a national priority. The Fleetzero, Thoma-Sea, and Glosten collaboration directly supports this objective by combining ultra-dense marine energy storage, vessel-level autonomy, and U.S. shipbuilding into a single low-signature platform.

"Moving cargo through contested waters is more imperative today than ever before. Fleetzero is building and demonstrating that capability today," said Steven Henderson, CEO of Fleetzero. "By partnering with Thoma-Sea and Glosten, we are pairing our Leviathan™ Energy Storage Systems and Fleetzero's autonomy stack with two of the most capable shipbuilding and design organizations in the country. This is how we can deliver MOSA-compliant, autonomous vessels at scale."

Fleetzero's autonomy strategy began with improving the propulsion system, a key enabler for eliminating maintenance required while in autonomous mode. Fleetzero's diesel-electric propulsion with the Leviathan™ Battery System unlocks long-duration autonomy missions. Fleetzero's Leviathan™ Battery Systems provide minimal noise and heat signature, engineer out unnecessary parts, and typically deliver double the energy density compared to other maritime battery systems. This reduces the total bill of materials to manufacture at scale, and dramatically cuts operating expenses over the vessel's lifespan while enhancing reliability and survivability in contested waters.

EXTENDING MISSION REACH THROUGH AMERICAN SHIPBUILDING

Thoma-Sea Marine Constructors, founded in 1989 and based in Houma, Louisiana, operates new construction yards in coastal Louisiana. Thoma-Sea was selected by the U.S. Navy's Naval Sea Systems Command to design and build the NOAA Oceanographer-class research vessels under a $178 million contract, and has delivered Navy-administered Foreign Military Sales vessels for allied customers. By integrating Fleetzero's power and autonomy systems into Thoma-Sea built hulls, the collaboration delivers a domestically built, autonomy-ready vessel that meets Jones Act and U.S.-content requirements for federal customers.

"Our yards have been building ships for American operators for decades," said Walter Thomassie, Managing Director of Thoma-Sea. "Partnering with Fleetzero and Glosten allows us to deliver the next generation of autonomous vessels with stealth capabilities ready for the missions our customers face today."

Glosten brings more than six decades of naval architecture and marine engineering experience, with a portfolio spanning research vessels, commercial cargo ships, and government platforms. As the lead naval architect for the system, Glosten integrates Fleetzero's propulsion and autonomy technologies with Thoma-Sea built hulls, engineering the platform's defining capabilities: low radar cross-section, silent transit, beach approach angles, and autonomous self-withdrawals.

"Bringing autonomy and electrification together at the vessel-design level is where this collaboration creates real value," said Morgan Fanberg, CEO of Glosten. "Working with Fleetzero and Thoma-Sea, we are designing vessels that are autonomy-native from the keel up, not retrofitted as an afterthought. The design is both functional and low-signature, built for decades of deliveries in the years ahead."

BACKED BY MOMENTUM AND INVESTMENT

This announcement follows a period of significant momentum for Fleetzero, which closed a $43 million Series A funding round in 2025. Fleetzero has been backed by both technology and shipping titans such as 8090 Industries, Y Combinator, Founders Fund, Obvious Ventures, Maersk Growth, and MOL Plus. The investment supports continued growth, advanced research and development at Fleetzero's Houston headquarters, as well as expanded partnerships such as the collaboration with Thoma-Sea and Glosten to bring next-generation electric autonomous vessel capabilities to market faster.

Fleetzero, Thoma-Sea, and Glosten are positioned to help shape the next era of maritime operations, where electrified power, autonomous control, and American shipbuilding operate as a unified industrial base.

About Fleetzero

Fleetzero is a Houston-based marine technology company building battery systems, electric propulsion, and autonomous vessel capabilities for commercial and defense customers. Fleetzero's Leviathan™ Battery Energy Storage System, Marine Battery Container, and Kraken DC-hub deliver high-density energy storage for the marine environment. Learn more at www.fleetzero.com

About Thoma-Sea Marine Constructors

Thoma-Sea Marine Constructors (TMC) is a family-owned, Louisiana-based shipbuilder with three locations and over 36 years of experience designing and constructing marine vessels. TMC is recognized as an industry leader with a proven track record of delivering high-quality, complex vessels on schedule and on budget. The company serves commercial clients across transportation, energy, research, and fishing sectors, and provides new construction, conversion, and repair services to federal customers including the U.S. Navy, NOAA, NASA, USACE, USCG, and Military Sealift Command, as well as state and regional authorities. Explore more at www.thoma-sea.com

About Glosten

Glosten is a full-service consulting firm of naval architects and marine, electrical, production, and ocean engineers. The firm's design experience includes research vessels, tugs, barges, passenger and car ferries, and other special-purpose vessels. Founded in 1958, the firm is recognized throughout the marine industry for integrating cutting-edge technologies and advanced analysis with practical, experience-based design. For more information, please visit www.glosten.com

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SOURCE Fleetzero