the introduction of vpps, or velocity prediction programs, morphed the science of yacht performance measurement. inherent to the ior was the concept of a measurement officer taking discrete hull measurements and the ior formula assumed the hull lines behaved continuously between measurement points. the ims took the actual hull lines and analysed their continuum, essentially eliminating funny bumps or hollows in the ensuing yachts and generally rendering much cleaner, faster lines that were far more exciting, safer to sail, and had higher resale value.