hi, we had a russian hydrofoil as inter island ferry a fewvyears back..to getbfrom st.croix to st.thomas,..it was the only transport,....it ran great.....until it cme off the foils....then as the hull met the water,..it was a rather violent event,...reviewing the americas cup races on u tube,..one can see the same thing.watching the speed read out reveals about a 50+%reduction in speed from foil to non foil mode....all of a sudden the 40knot ac72 is going14-16knots.....so to defeat the boat on may manuver to cause the opponant to come off foil,..simple, yes?the price of the russian ferry was reasonable, but the stench of the sea sick passengers, negated the price...just a observation..no need for any one to get shook.have a great day!