|Diameter and pitch should be weighed heavily when choosing a propeller. The diameter is the width of the circle traced by the rotating blade tips. Pitch is the number of inches a propeller would move forward in one full revolution with zero slip.|
The number of blades is yet another variable to consider when selecting a propeller. "Three blades are the most efficient because they swing around quicker and bite fresh water," explains Dave Meeler with Yamaha Outboards. "They also produce more speed since there is less drag." For boats like flats skiffs that require more stern and bow lift, along with quick planing capability, a four-blade propeller may be the better choice.
Many inboard-powered boats are switching to five-blade propellers to boost speed and cruising ability, says Robert Martin, the general manager for Bobby Soles Propeller Sales & Service in West Palm Beach, Florida. "Everybody is speed-conscious today," he says. "Most vessels will cruise at a respectable 30-plus knots." To handle the rigors of increased diesel horsepower with minimal slippage, many offshore sport-fishing boats use pricey custom wheels with wider blades. Nibral, a nickel, bronze and aluminum alloy, is the material of choice. Custom propellers like the Australian-made Veem brand can cost up to $20,000 each, according to Martin.
The average boater isn't going to have to spend that much to realize better performance. Many dealers offer propeller demo programs, so you can try various models until you find the one that best matches your expectations and needs. "Determine what's the most important when you're on the water," Mercury's Ben Duke advises. "Do you want more top-end speed, a better cruise or good fuel economy? Do you need more bow lift or a better hole shot? If so, there's a propeller out there. It's just a matter of trial and error to find the right one."