There are multiple electric ferries already in operation:
https://en.wikipedia.org/wiki/MV_Ampere
They are quite impressive but they are still very far away from your average ocean going cargo vessel.
Yeah, the oceanic part is the issue. Going between two close points, at least one of which has electricity, is easy.
Electrifying ferries is great, but this particular one has a run time of 20 minutes (and a charge time of 10 minutes). I get a totally different vibe from 'oceanic ship' than a 20 minute ferry ride.
Near me, we now have a hybrid ferry, no charging infrastructure, but it still uses much less fuel than before it was refit, so that's cool too. It's bigger than the one you linked and sails on a longer route: 2,499 passengers, 202 vehicles, typically serves an 8.6 mile route.
https://en.wikipedia.org/wiki/MV_Wenatchee