We had a thread ages ago...
Continuous wave an excellent web site, but unfortunately the formula are now only in equation form , not as a calculator.
Even so its not just a matter of dropping numbers in to a calc without having some understanding of the following.
The majority of plaining hulls have changed dramatically since crouches time..the biggest change is the number of trailer boats, rather than moored , which limits hull width... and we have calculators not slide rules... Crouch based his formula on square root, when most force/ weight formula are cubed root. On a slide rule a quick calculation on a slide rule requiring cube root is not quite that simple.
Also Crouch was not just designing smaller plaining hulls but boats like PTs and lesser extent the veramile of WW2. These tended to have a constant hull contact with the water, where as modern boats tend to lift higher out of the water the faster they go. Therefore unlike yrs ago modern hull dont have a constant constant, unless min or underpowered
These all have an effect on hull constants for modern plaining trailer boats.
Thats just for calc what power (HP) is required for a hull of given weigh to travel at a given speed on flat water at best trim...give or take a couple mph.
Then comes the calculations to match a prop to the above, which is pretty straight forward
Unfortunately the threads which we have been doing the calculations have got so many 'caveman' type spam posts.
So all that has gone to PM, usually personal emails, and face to face communications
Therefore the data, number crunching, explanations why and hows never got published.
What has bee of notice is the number of new and re powered boats the owners have been disappoint in performance.. messed with different props , only to find they just dont have the power to support the required prop to meet those expectations.
Few have had excellent results, being min to well powered...30 to 45% increase in economy and 4 to 6mph better cruise speeds, and increase in WoT
And a couple, who where quite happy with what they had, but wondered if there was a little more...1 there was a tiny bit more but not worth the capital expense of new prop, the other was between 2 prop choices so had the best any way.
The guys at Continuous wave and other pubic sites also take 'caveman' flak, not different to here. All because they
may mess with crouches formula and find it doesnt work very well because of a lack of understanding as explained above.
So on that basis, because of a small majority, maybe a open area to work this stuff out is not such a good idea??