The Maori translation is a bit off, as it says that the (poorly translated) hovercraft is made with a peak amount of eel (not plural). It seems a fair number of these translations do not connotate that the hovercraft is filled with eels (plural) but rather that it is an eel (singular) that is taking up a lot of room in the hovercraft.

In general, if you go to google translate, you'll see that this phrase is not well translated. Hovercraft is a tough one in general, and some languages don't have an eel in their vocab. Still, it shows that text translation is not very easy, as environment, persons speaking, and context really matter.