Comments: - These have been in use in Japan for a long time. I lived in Japan in the 70's along the coast near Zushi . There was an old guy who had one of these machines and he would drive it up and down the beach from town to town cleaning out these mooring areas for the local fishermen. It was a lot of fun to watch.

Holy hell i was expecting to see an operator with a aqualung sitting in the seat operating it until i spotted the guy with the controller. Dammed amazing.

"How did that go again? Triangle, circle, cross, cross, square.. no, triangle, circle, square, square... dammit, I'll never get this cheat memorised..."

This seems extremely inefficient.  Yes it is pretty cool but I can think of several different ways to accomplish that job faster, cheaper and better.  Drag-lines and dredges come to mind right off the top of my head.

Lots of people are saying that this is too slow or the wrong way to do it, that dredging would be better. But Japan only has a limited number of dredgers available. After the tsunami they had hundreds of harbours this size to repair and nowhere near enough machines to do it. Especially since many of those dredgers were also wrecked by the tsunami. So they did what the Japanese often do: they got creative and adapted what they had to hand. I think these machines are another fantastic example of Japanese ingenuity.

This is incredibly cool but soooo much more stupid than cool. It's too slow and plus how long will that machine last in the saltwater? They have underwater vacuum things that make more sense or even a crane dredge would make more sense