This sailboat hovers above the water

Image: Tilly Lock, YouTube

You might spot an interesting-looking sailboat in Mission Bay, a boat that moves fast and appears to hover just above the water. These small sailboats are called Moths and there's plenty of science and engineering that went into making this watercraft the agile speedster that it is.

How does the boat lift out of the water and how does this design increase performance? What can we see above the water and what is not visible under the water? How does an airplane lift upwards and how are those principals similar and different than those on a Moth?

Resources:

YouTube: 2017 Australian National Moth Championship

MIT: Tina Rosado, Hydrofoils

The Inertia: How Hydrofoils Work