First of all, the formula I gave calculates the speed in knots, not miles/hr. That would change the figures I gave to PA12 = 5.34 miles/hr and PA14 = 5.77 miles/hr. Sorry for the mistake.
Hull Speed is not the maximum speed that a given boat can reach. It's supposed to be the point, where in order to go faster, the boat has to climb up over its bow wave. This can be done, but takes a disproportionate amount of effort for the amount of speed increase you get. Racing kayakers exceed the hull speeds all the time, but they're putting out a lot of effort. Furthermore, the formula I gave is just a general formula for displacement hulls and probably doesn't accurately transition to the narrower hulls of pure kayaks. The Revolution 13, which is closer to a true kayak, is certainly not the same hull design as the PA's, so that's comparing apples to oranges.
The PA12 & PA14, however, are nearly identical in hull design and fairly close in weight. Regardless of which formula you use, if the two boats you're comparing are fairly similar, a longer waterline will generally result in a faster boat. That was the only point I was trying to make. As I said before, there's probably not that much difference anyway. I was just having trouble seeing how the shorter PA12 could be faster?
Tom Kirkman wrote:
The Revolution 13 will easily outrun either of the PA's - it'll do 7 MPH in a sprint (maybe even faster with somebody else pedaling) and cruise easily at 3 to 5.
I own 4 Hobies and every single one of them will run one heck of lot faster than the theoretical hull speed. I'm not arguing with physics - I'm saying it's not being applied correctly. You can keep any of these boats going faster and faster until and unless you can no longer steer them in a straight line. And none of them hits the wall at just 4 or 5 MPH. The only limit as they ship is your ability to pedal the Mirage Drive.