apparently, 40MWh of capacity is enough to travel 40 nautical miles. The distance between Tasmania and South America is around 6,500–7,500 nautical miles.

For comparison, a wide body airliner needs ~0.15MWh to travel 1 nautical mile.

A wide body airliner doesn't carry "up to 2,100 passengers and 225 vehicles".

It also does so in a medium where the main drag force is induced by air rather than water, which is probably a comparably significant factor

It also needs to beat up that air enough to make the resultant forces overcome gravity acting on the airliner whereas the ship just gets to float there.

Apples to orages.

Yup.

Or to structure it a the earlier comment: for comparison, it takes me about 0.000065 MWh to cycle 1 nautical mile.

That's a couple of apples.

You also aren’t doing so while carrying 2100 passengers sms 225 cars, I imagine.

Plus they are going to get very waterlogged cycling that nautical mile.

Some dedicated cyclists will cycle in any weather.

And a maglev train?

https://en.wikipedia.org/wiki/Maglev

I would be extremely surprised if the ship were designed to use 100% of its capacity in one way of its intended route.

The drag on a vessel is orders of magnitude larger than the drag on a car.