Consulted with Mike Heller on the right prop for my Boston Whaler 13.5 ft with 30 HP Mercury. Boat was slow to get on plane and struggled with a full bait tank. After sharing current prop size and pitch Mike suggested a 1 inch larger circumference and 1 inch less pitch. This made a big difference and still kept the motor within maximum allowed rpms. Very please with the customer service and shipping experience.