Want better performance out of your boat?

                                                                                                

     

Look first at your propellers!

Marine propellers are complex products, designed to transform a spinning shaft into forward thrust. Unfortunately, the finest designs are compromised by inaccurate manufacturing, resulting in pitch deviations across the surface of each blade, deviations from blade to blade, and deviations from propeller to propeller. At the high rotational velocities characterizing modern performance propellers, deviations of as little as one millimeter cause the propeller to impart an up-and -down motion on the shaft and a deflection of the blades with each rotation. Moreover, even a "perfect" propeller, improperly sized to the boat/engine/transmission, will result in poor top-end performance and/or excessive engine loading.

Variations in propeller structure, either across the blade surface, blade-to-blade, or propeller-to-propeller, result in notorious problems for boat owners.

	Excessive vibration wears out drive trains and bearings, reduces thrust, and causes an unpleasant experience for captains and guests.
	Boats achieve plane slowly, do not reach maximum speed, and fail to develop specified rpms. Premature engine failure results.
	Propellers cavitate, resulting in lost thrust, “burn”, early replacement, or ultimately, blade failure.
	Boats burn more fuel than necessary.
	Captains must play with controls to get, at best, satisfactory performance.

Propeller "size" is really its potential to deliver thrust. The primary propeller characteristics that determine thrust are diameter, average pitch, the relative amount of blade area (the so-called Disk Area Ratio, which can be greater than 1.0 for overlapped blades), and blade camber (the pitch profile at a given radius, from leading to trailing edge). Propellers sized too small for the boat will result in quick rpm run-up and a low top speed. In the absence of a governor, the engine will over-rev at WOT, and ultimately fail. Conversely, propellers sized too large for the boat will result in sluggish performance at rpm run-up, a low top speed, obnoxious black exhaust smoke, engine overheating, and premature engine failure. "Perfect" propellers properly sized when the boat was new will become oversized after a few season's use as the boat gains weight from water absorption and owner "improvements" ( a 10-ton boat will commonly gain 2 tons after a few years). PropTech will re-size your propellers to your boat's current state, recovering lost performance and returning your engines' operating range to that specified by the manufacturer.

PropTech is certified to offer propeller inspection, tuning, and repairs based on the world-leading PropScan ^TM measurement technology.  PropScan^TM is the first computer-aided scanning system dedicated to propeller analysis, tuning, and repair.