Technically I think it’s human powered. They wouldn’t need to register it. It would fall under the same classification as a rowboat with out a motor. They did wander a bit close to the cruise ship security zone, so that should be questioned.
That’s one of the issues - port security. In my neck of the woods, canoes, kayaks and the like all need a license - if it floats, they tax it and regulate. These dudes should’ve used their noggins a bit more than engineering the craft.