How do we do all this?

SpeedboatPerformance.com employs a full-time Naval Architect
whose work has been published in multiple professional journals.
We have developed all aspects of the numerical computer code
responsible for your performance prediction, in house.  The code
runs on our servers, so there is nothing you need to download
or install. Our Naval Architect originally developed the code to set
up his own high-performance boat, and avoid costly mistakes.