"You always have to have something new or you're not going to last long in this business." That's what the guy at one prop shop tells me over the phone. While I applaud his pioneering spirit, it makes me wonder how many propeller developments are real improvements and how many are just empty technology used to increase sales rather than boat performance.

Certainly it's a rich topic for the occasional false promise. The intricacies of pitch, diameter, cup, and rake angle among a host of other variables create a mathematical conundrum that can leave even the most experienced mariner scratching his head. "Let's see, if take a little cup out, drop an inch in diameter and go from a three-blade to a four-blade, what does that do to my acceleration?"

I'll be the first to tell you I don't know the answer to that question, but I have an idea. That's because I've familiarized myself with the basics of prop performance, which is the first step in avoiding spending good money on bad wheel technology. Assuming you already know your rake from your exhaust port, the next step is to know what's new and keep up with the dockside scuttlebutt about what actually works.

Luckily, we've already done that for you. Here, then, are the hottest things going round the world of prop development. They include blueprinting, improved exhaust venting, and one-piece construction. If you want to pick up a few miles per hour, increase you acceleration or just improve the overall performance of your boat, take a closer look.

Get the Blues

Blueprinting is by far the fastest growing area of propeller tweaks. It's a process by which propeller experts examine your boat-prop relationship then custom finish your prop to maximize performance. It can add mph instantly, and it's surprisingly more affordable than you might think.

The process involves an examination of your boat performance. They consider things like horsepower-to-weight ratio, load, hull design and stability. Then based on years of experience and a little number crunching, they add or take out cup, alter pitch, and even possibly make the blades thinner.

Last year, as part of a test, Mercury Racing took a 25-foot boat with a standard 454, a Bravo One drive and an out-of-the-box, factory-recommended prop. Afterwards, they blueprinted the prop to fit the boat more precisely and retested it. The boat was five mph faster! Normally you have to change engines to pick up that kind of speed.

For the extra nickel on your speedo, Mercury charges a paltry $350 — that's $70 for each mph improvement. Not everyone will get the same results from blueprinting, but it's exciting to think that it's possible. It certainly isn't stopping many people from trying. Prop shops around the country are paying their rent performing blueprinting services, and Mercury says they have 11 technicians in their shop who do nothing but blueprint from morning until night.

Get Vent

Another interesting area of development involves venting the exhaust into the blade area. Traditionally, props vent exhaust directly through the center of the hub, which ensures that aerated exhaust water doesn't get into the blades. Lately though, some have begun experimenting with venting a limited amount of exhaust through the outer hub into the blade area, with some surprising results.

Mercury Marine Propeller Company's vented propeller configuration is called the Performance Vent System. Among the more notable PVS offerings is the Revolution 4, a four-blade wheel that has reportedly delivered strong performance gains in certain applications.

OMC has just introduced a 30-inch pitch to its Raker props, a line of aircraft-quality, high-polished Stainless steel wheels. In these props, vent holes in the outer exhaust hub let exhaust gases ventilate blade area. Once ventilated, the water provides less resistance, which allows the engine to build up rpm. Along with high rake and cupped blades, both of which increase bow lift, the increased rpm push the boat on plane faster. At higher speeds, the water rushing past the hub blocks the vent holes, preventing them from ventilating the blades.

Stiletto Performance Propellers provides another take on this idea of venting the blade area. Their props also vent exhaust through the outer hub ahead the blades. In this case though, the positioning of the vents allows the aerated water to break up speed-sapping vacuums that can form behind the blades.