How fast did the first hydrofoil go?

The first hydrofoil, the "Hydrofoil No. 1," designed by Alexander Graham Bell and his team, reached a speed of about 18.3 knots (approximately 21 miles per hour or 34 kilometers per hour) during its trials in 1919. This marked a significant achievement in hydrofoil technology, demonstrating the potential for faster and more efficient watercraft. Subsequent hydrofoil designs have since surpassed these speeds dramatically.