If anyone's confused about 10x in the GP post and 2-3x in this one, a given size boat with a displacement hull might have a hull speed of 6 kts and with a planing hull a hull speed of 5 kts.
At 2 kts, they'd both probably be in displacement, but the planing hull would be using 2-3x power.
At 6 kts, the planing hull would be using about 10x power, because it would be operating in planing mode while the displacement hull is still operating in the very efficient displacement mode.
At 2 kts, they'd both probably be in displacement, but the planing hull would be using 2-3x power.
At 6 kts, the planing hull would be using about 10x power, because it would be operating in planing mode while the displacement hull is still operating in the very efficient displacement mode.
Only the planing hull could exceed 6 kts.