Hawaii is looking at running some next year.
https://www.sfgate.com/hawaii/article/hawaii-electric-airpla...
I'd expect ferries and/or small cargo ships to be an attractive option if allowed.
The challenge when moving goods via ocean vessel is that everything takes _a long_ time. Loading and unloading the vessel can take days. Transit is weeks. Unloading the vessel takes days.
You have 2 options now: air freight which is crazy expensive but gets it there in a few days max or ocean freight which is relatively cheap but might take weeks. If you can cut out vessel loading/unloading you save at least a week.
Air freight is also an odd comparison since it's usually time-sensitive and/or pricey ($100+ per pound).
What I don't understand is that they are talking about running it trans-Atlantic. Taking longer than a normal container ship, while taking less cargo. You save on fuel, but surely the crew costs must be eating up all those savings. And you're not really faster. Unless the plan is to go point-to-point between smaller harbors, making up any lost time by saving on cargo handling time
A lot of containers take a small-ship trip after the big-ship one.