Came here to say the same thing. At the scale of container ships, almost all the disadvantages of hydrogen are gone. Storage, cooling and leakage should all be controllable, given large enough tanks.
Interestingly enough, there's some prior art in the German Type 212 submarines, looks like it's production ready: https://en.wikipedia.org/wiki/Type_212_submarine
It's probably only about cost and infrastructure. Does anyone have current details on the price of massive diesel engines vs. massive fuel cells and electric motors?