I have a 96 Cabrio 28 with Twin Merc 4.3. I am running 17P Vengeance Props. My Hole Shot is terrible. The boat Cavitates and eventually comes on plane. I was told by a Larson dealer that this is due to the Delta Conic Hull design. Once planing, you need to keep the boat at a minimum of 3600 RPMS to stay on plane. At 3600 RPMS the boat only cruises at about 21 MPH. My WOT is 4800 RPMS. The boat does about 39 MPH at 4800 RPMS. I tried my friends 21P 13 3/4 props, and my Hole shot, and cruise speed improved, but my WOT was only around 4000 RPMS and top speed was about 30 MPH. Based on this, I bought a set of 19P by 14" props. This did not seem to be much better than the 17P and my top speed was still only 32 MPH. Any suggestions? I don't understand the advantage of this hull design unless your runnig at full throttle all of the time.
