threw on a new prop today. The boat came with a 15 1/2 x15,which works just fine. I got outta da hole real nice,cruise about 29-30 mph at 3900, WOT about 36-37 at 5200. I was really going for a spare prop so I stayed w/ a stock 3 blade aluminium 15x17. Little change outta the hole, picked up a little speed on the cruise and a little bit on the top end...RPMs stayed nearly the same on both [I thought they'd drop a bit] All in all, the 15x17 is now my prop,the 15 1/2 x15 is the spare.P.S. while taking my test run I got into HUGH schools of bluefish chasing peanut bunker,the water was completely boiling w/fish. All 2,3,4lbs. its fun ,but, after the 20th release I have had enough.Not my favorite quarry but they fight like mad.