Panda,
my boat is considered a 24ft boat (but it’s actually closer to 25.5 feet). I think your dads 22 footer may be similar (closer 23 or 24 feet). Also my boat hasn’t done 40mph no matter I’ve done (even since new). I have had Bimini up and down, I have gone with the family (4 of us) as well as by myself, loaded with coolers and cargo and no cargo, full tank of fuel and 1/8 tank of fuel. I have gone out with 12-18” waves as well as flat water. None of it makes a difference it will still not do 40’s (really doesn’t do 39 either). It stays right at 38-38.5 mph (I have 3 different gps devices as well to confirm speed). My boat lives on a trailer when not in use (it is not left on a lift, or floating in the water). To clarify
Empty boat (no cargo), myself only, 1/8 tank of fuel, bimini down, flat water= 38.5mph
loaded boat (up to 9 people on board is most I’ve had, 4 full coolers, full tank of fuel (42 gallons), Bimini top up, in 8-12” waves= 34.5-35mph
plus my boat’s dry weight is 2215lbs (my decking is composite and not wood. There is no wood on my boat at all). Also dry weight of the engine is 475lbs (let’s call it 550 with fluids). So that means my boat should weigh in well under 3k when I have my “empty boat” scenario from above.
also I used your calculator and based on the info I entered, my prop slip is 4.51% (I have a 13 pitch, 3 blade stainless prop and turn it to 5920-5980rpm).
I have heard of several guys with different brand boats, similar size (dealer/mfg calling it a 24 footer) with 150hp engines running 40mph.
I just feel this boat should easily be low 40’s especially in my “empty boat” scenario.
Thanks for all the info guys!!