I am the owner of a 21 ft Tri Toon Lowe Suncrusier. With a Mercury 115 four stroke. I am playing find the right prop game. I'm am wondering what would be the best for the boat. I have been running 2 different ones. (1) is a blackmax 13.75 X 15 and it turns about 400 to many RPM's. So i have a 13.25 X 17 blackmax and it is not turning enough. What is my best option for this boat. PLEASE HELP.
