When I crossed from Vietnam to Cambodia, our transportation from the border most of the way to Phnom Penh was this boat. I'm about 99% certain that it's a retired hydrofoil. Why throw away a perfectly good boat hull just because it doesn't work as a hydrofoil anymore? Rip the fins off and throw it back in the water with a big diesel engine in it. The air circulation inside the body was so bad that most people ended up outside - it was cooler in the sun than inside in the shade. The ride took about three hours - not exactly hydrofoil speeds.