A race is being run by nuclear scientists and ship designers. The prize? “Decarbonization’s” holy grail — believed to be a “small” thorium-fueled, molten-salt rector’s unlimited power to propel sea trade. At the same time, a recently revived discussion among leading marine-nuclear thinkers revolves now around how to put an ultra-modern, as-yet non-existent marine reactor aboard a modern commercial vessel. As with nuclear power generally, shipborne reactors produce national discussion first, then discovery.