"Liberty Lifter" DARPA Ekranoplan

Umm Why?

There are so many other modes of transport in existence that will do the same thing, it won't be any good for things like disaster relief as there is generally so much crap floating around in the sea after storms/tidal surges etc. that it will be too dangerous to land it, there is no way any sane military would use something that big and slow for resupply.

I really don't understand the purpose to it.