I guess we should be assuming at least some slight wave assistance but even then it is mind bogglingly, stupendously, amazingly fast!!!

Questions that spring to mind:
-How fast does this thing go square to the wind? (assuming that they didn't have a near perfect angle - 110/120 degrees?? - all the time)
-If you scaled this gigantic craft up even larger, would it just go even -GASP!-
faster? (assuming it would hang together

)
-Are the foils starting to cavitate? (sorry, I just had to ask...

)