PT50 hydrofoil Long Reef approaching Manly one weekend in 1988/89. Roll induced by helm and flap movements on final approach to wharf. This hydrofoil was ex Freccia di Mergellina seen in movie Avanti.
Martin, only 2 years to reply to your comment! The roll in smooth water was caused by a combination of flap and rudder movements on final approach to the wharf in conjunction with a poor decision by the Engineering Superintendent of the day to add sections to the trailing edge of the bow and stern foils to increase lift to decrease take off times and to be able to run at reduced revs to reduce fuel consumption at same flying height. It produced the opposite effect and ruined handling
Garry, I would also say a contributing factor to the onset of the roll motion may have been that the hydrofoil is flying quite high at the bow foil which means it has less roll stability. The guys must have had the throttles at maximum!
