Foiler Flying Yacht hydrofoil boat - GIF

[suther51]

"They are not able to travel on their foils at slow speed .......... so they use even more fuel at slow speeds(the foils drag) than regular boats do at same speed."

The navy ships that I am slightly familiar with the foils folded up for normal operation. By the strange recesses on the hull of this one I would dare guess these foils fold up also.