The one on the right looks like it's ducted fan or turbine powered...[8D]
(or would be rather...)
I was talking to an old friend last night about boats...
He's 78 now, and has designed and built several 1:1 boats over the years...
The tether boats in the pics above have the center of flotation or bouyancy rather aft...that would lessen the tendency to squat under acceleration...and lessen the tendency to "blow over"...that was one of the things my friend talked about. (sponsons in the rear )
He raced small O.B. powered boats when he was (much ) younger...he said his were always at least a little bit faster than the traditional designs because he designed his with his model airplane experiences in mind
(He had one with the top "deck" made of a stringer and fabric covered construction, similar to a stick and tissue model airplane )