A special foil assist system was developed for the Halter Marine E-Cat ferry demonstrator which has semi-displacement demi-hulls and operates at relatively low Froude Numbers but sill allows improvements of 40% against the E-Cat without foils. Trials were run off New Orleans and confirmed the predicted improvements. Later wash measurements confirmed that the wake of the E-Cat with foils was considerably lower than of any other high speed ferry. With 175t to 182t the E-Cat reached 46 knots top speed even though the foil design was optimzed for 40 knots. Propulsion is by twin Caterpillar 3576B 1,910 kW Diesel engines and Bird-Johnson 650 waterjets. The transport efficiency in inversed form ep = 0,103 at a Froude Displacement Number of FnD = 2.92.