Maritime Fusion is designing a compact tokamak fusion reactor that will be installed on oceangoing vessels rather than on land. Leveraging advances in high-temperature superconducting (HTS) magnets, AI-driven design, and modern computing, the startup aims to deliver safe, meltdown-free fusion power directly at sea, where it can compete with costly alternative marine fuels like ammonia and hydrogen. The company is already assembling HTS cables from Japanese-sourced tape; these cables will both serve its own reactor and be sold to third parties to generate early revenue. Its first planned power plant, dubbed Yinsen, is expected to generate roughly 30 MW of electricity, measure about eight meters across, and cost an estimated $1.1 billion to build. Maritime Fusion projects Yinsen will be operational by 2032, with certain ancillary processes such as fuel handling performed on shore to simplify onboard systems. Unlike some competitors developing demonstration-only machines, Maritime Fusion intends for its first tokamak to deliver commercial power to a paying customer. The company participated in Y Combinator’s Winter 2025 batch and is led by co-founder and CEO Justin Cohen.

Total raised

$5M

Funding rounds

1

Latest round

Seed

Latest activity

Nov 2025