 This led to a string of very successful Merlin Rocket designs such as "Satisfaction", "Smoker's Satisfaction", "Summer Wine" and "NSM" (New Smoking Material).Morrison's designs won every Merlin Rocket Championship for 17 years from 1972 to 1988.See Merlin Rocket Designs and Merlin Rocket Design Guide and Keith Callaghan's, a rival designer, memory of Morrsion's eventual supremacy in the Merlins Merlin Rocket Design Guide

His next step was to design an International 14, "Snoggledog", built by Laurie Smart, with which Morrison and Ray Sellings took second place in the Prince of Wales Cup race in Torbay in 1973, their second year in the class.