I should have posted that the boat your looking at is a 56" catamaran with SSS5694 1200kv motors running on 8s lipos and sport runs with 6s. The props are stainless 5517/3.
I shure would like to see a video of your boat with those 75mm props! please let me know what kv the motors are nad the lipos that your using. if you under 20000 rpms I could see how this could be a fast boat. 75mm are a gas prop and so the rpms are 18000 or less with gas! Run higher than that and you will smoke esc's and motors!!!