It could make ammonia from air and water. Current engines can be modified to run on ammonia.

Fueling can be done in an hour.

Power storage feels like a complete non-starter, without radical breakthroughs. It'd be vaguely interesting to run the numbers & see what % of a ship would need to be hydrogen gas storage, perhaps. Whether that is for a single leg of a jaunt makes a big difference. I wonder how often cruise ships tend to refuel.