This might be of interest to a few.
With the lengthening from 38 feet to 42 feet, the calculations had to be redone and unfortunately, it did not actually improve some of the more unwelcome numbers.
There are factors increasing speed and at the same time, factors reducing speed. For example, the deep V of the centre hull, at 3 feet wide and 42 feet long, has a double effect. It sits the boat deeper in the water, giving stability of tracking but it also increases wetted area, which slows the boat but the overall lightness and length makes her respond more quickly to the water pressure, i.e. the hull is forced upwards by the Vs in both centre hull and pontoons, not unlike a hydrofoil, reducing waterplane or wetted area and increasing speed.
She’s rated at 8.68 knots and will do up to that on a pond, with no other factors involved other than wind.…