One of the advantages of hydrogen is that tanks and fuel cells can withstand a large number of "charging cycles" much better than batteries. Additionally, for ships, the amount of energy needed to move is so enormous that I fear we'll have a hard time creating batteries that are feasible for long-distance shipping.

For short distance ferrying (including large, car carrying ferries) on the other hand, Norway has already implemented quite a few electric stretches. The major issue there is building the infrastructure to charge the ferries.