https://www.techradar.com/news/toyota-sends-autonomous-hydrogen-powered-ship-on-a-six-year-world-tour

Toyota is sponsoring the world's first autonomous hydrogen-powered ship on a six-year world tour. The specially adapted race boat, Energy Observer, uses solar, wind and wave-generated power – as well as carbon-free hydrogen generated from seawater.

The base technology already exists for use on land, where it helps overcome the problem of intermittent power supply from renewables, but this is the first time it's been used at sea to produce hydrogen 'live' during stopovers and navigation.