[Bruce_Sailboatdata]

Measured hull speed in a displacement hull is a function of LWL. The difference in the reported LWL of the 34 and 320 is ~10″. Theoretically, both can achieve 7 kts. Actual hull speed depends on a number of factors. Our suggestion is to search Catalina 3 on our website then compare the two models. Doing that should help answer your questions.