Fundraising Fox
/Companies
Sign in

Maritime Fusion

YC W25

San Francisco, US · Founded 2024 · 6 employees · Hiring · 11 known investors

Find your way into Maritime Fusion

Sign up to see every warm intro you have to Maritime Fusion

  • Paths you didn't know you had: your email and LinkedIn already hold routes to the Maritime Fusion team. We find them for you
  • 2nd- and 3rd-degree connections: the friend-of-a-friend routes that take hours to manually find through your inbox or LinkedIn
  • Answers now, not in days: momentum is everything in a raise. Skip asking around whether someone knows someone

Days of research, done the moment you sign in, with every route ranked by how warm it is.

Sign up with GoogleAlready have an account? Log in

Maritime Fusion designs and builds zero-emission fusion reactors for deployment in maritime transport and remote energy installations. The company aims to use these off-grid applications as a pathway to develop cost-competitive grid-scale fusion reactors.

Advanced ManufacturingCleantechDeep TechEnergyFusion EnergyHard TechUnited States of AmericaAmerica / Canada

Founders & leadership· Y Combinator alumni (W25)

Maritime Fusion was founded in 2024 by Justin Cohen and Jason Kaufmann.

JCJustin Cohen
Justin CohenCo-FounderJustin Cohen is a nuclear engineer and plasma physicist who previously held roles at Tesla, SpaceX, Princeton Plasma Physics Laboratory, and NC State, as well as attended Columbia University. He now leads Maritime Fusion, developing fusion reactor technology.30 Under 30 2026
JKJason Kaufmann
Jason KaufmannCo-FounderJason Kaufmann studied physics and computer engineering at Penn, and has worked on hardware engineering roles at Tesla focused on AI systems and at SpaceX on power systems for rockets. He is now developing fusion reactor technology for maritime applications.30 Under 30 2026

Investors · 11

Aera VClisted by Aera VCSingapore · $25K – $5M

How we know: Aera VC's portfolio page · funding news · the VCSheet dataset · open dataset · 5k.vc investor directory · Y Combinator's founder network · Not right? Tell us

Alumni Ventureslisted by Alumni VenturesManchester · $100K – $10M

How we know: Y Combinator's founder network · av.vc · Not right? Tell us

Avant Labslisted by Avant LabsBangkok

How we know: Avant Labs's portfolio page · Not right? Tell us

Trucks VClisted by Trucks VCSan Francisco

How we know: Trucks VC's portfolio page · funding news · finance.yahoo.com · the VCSheet dataset · Y Combinator's founder network · Not right? Tell us

Y Combinatorlisted by Y CombinatorSan Francisco · $500K

How we know: the Y Combinator directory · funding news · open dataset · 5k.vc investor directory · Not right? Tell us

Batch Venturesreported

How we know: Y Combinator's founder network · Not right? Tell us

Metsu Capitalreported

How we know: Y Combinator's founder network · Not right? Tell us

Network VCreportedMenlo Park

How we know: Y Combinator's founder network · Not right? Tell us

Schox Venture CapitalreportedLynnwood

How we know: Y Combinator's founder network · Not right? Tell us

Stanford UniversityreportedStanford

How we know: a partner's Signal profile · Not right? Tell us

The Riverside CompanyreportedCleveland

How we know: Y Combinator's founder network · Not right? Tell us

Funding

SEC filings, press & company announcements

$9M disclosed across 2 rounds · 2025

Source: company announcements and press reports — follow each round's link for the claim.

Related companies · 6

Tri Alpha EnergyTAE Technologies develops hydrogen-boron (aneutronic) fusion power using a beam-driven Field-Reversed Configuration reactor design, aiming to deliver utility-scale fusion electricity to the grid in the early 2030s. Through its subsidiaries, the company also works on grid energy storage solutions and cancer treatment technologies.
Helion EnergyHelion develops fusion energy systems designed to generate clean electricity for commercial use. The company builds pulsed magnetic fusion prototypes with applications for industrial and commercial electricity generation.
Zephyr FusionZephyr Fusion develops compact, in-orbit fusion power systems for space-based applications including microgravity manufacturing, data centers, defense, propulsion, and human habitation. The company leverages fusion technology to provide megawatt-class power generation for space industry customers.
NODI EnergyPWR Matrix develops simplified power delivery architectures and semiconductor innovations to improve energy efficiency for advanced applications including AI infrastructure and electronics.
Libra RoboticsLibra Robotics builds autonomous robots for solar farm installation at utility-scale and commercial projects. The company serves electrical contractors, equipment manufacturers, and solar project developers.
Ethos Space ResourcesEthos Space develops technology to build and operate spaceports and infrastructure on the Moon using in-situ lunar resources, including construction material (Durandal), onsite propellant production (Prometheus), and materials for space-based data centers. The company also publishes research reports on lunar and planetary resources such as silicon, water, critical minerals, and helium-3.

Companies working in the same space as Maritime Fusion.

Legal entities · 1

corporate structure
Maritime Fusion, Inc.

In the news

Maritime Fusion Raises $4.5M in Seed Fundingfinsmes.com · Nov 2025Y Combinator-backed Maritime Fusion Raises $4.5M From Trucks VC, Paul Grahamfinance.yahoo.com · Nov 2025This startup wants to build a fusion reactor — on a boat | TechCrunchtechcrunch.com · Nov 2025Maritime Fusion - Fusion reactors for shipsycombinator.com · Feb 2025

Frequently asked questions

What does Maritime Fusion do?
Maritime Fusion designs and builds zero-emission fusion reactors for deployment in maritime transport and remote energy installations. The company aims to use these off-grid applications as a pathway to develop cost-competitive grid-scale fusion reactors.
Who founded Maritime Fusion?
Maritime Fusion was founded by Justin Cohen, Jason Kaufmann in 2024.
Who are Maritime Fusion's investors?
Maritime Fusion's investors include Aera VC, Alumni Ventures, Avant Labs, Trucks VC, Y Combinator, Batch Ventures, Metsu Capital, Network VC and 3 more.
How much funding has Maritime Fusion raised?
Maritime Fusion has disclosed $9M raised across 2 rounds.
Where is Maritime Fusion headquartered?
Maritime Fusion is headquartered in San Francisco, US.