Sharrow Propellers (2022) - Test Video by BoatTEST.com

hi i'm captain steve for boattest.com and today i'm here on what i think is a very important mission for every boater who's trying to get peak performance out of a boat it was almost exactly two years ago that we tested the radically different cheryl prop and it was an invention of greg sherrow nearly 10 years before and during that previous 10 years show had secretly developed and refined the design of his new prop concept collaborating with some of the most expert prop designers testing facilities and manufacturers in the world our test two years ago was the first time that this unusual prop was introduced to the world at large we took a cheryl aluminum prop and put it on a single 150 horsepower mercury outboard that powered a 20-foot bow rider that weighed 3 543 pounds we then tested the boat with two other stainless steel conventional props so that we could compare the difference in performance among the three props what we discovered was that this radical prop design was also revolutionary we found that the sheryl prop was faster in all rpm settings planed at lower rpm and had more thrust in reverse stuck to the water in tight high speed turns and had significant improvement in miles per gallon at nearly every speed setting particularly in the mid-range but over the last two years people have asked if this was just an anomaly some prop experts even said that every pop has its sweet spot application and cheryl just happened to find the boat best suited for its design while the cheryl props might be better on a small lightweight monohull with a 150 horsepower mercury outboard how would they do on a larger heavier boat with a different hull shape and powered by twin 300 horsepower engines to answer all these questions and more cheryl marine asked botest to once again test their props and compare them to the standard stainless steel wheels the engine maker recommends this time we're testing a 32 foot world cat catamaran instead of a monohull with two 300 horsepower yamaha engines instead of a single 150 horsepower mercury and about weighing 13 694 pounds four times heavier than the one before with four times the horsepower the first props we're going to test on the yamaha engines are the ones that come standard yamaha's saltwater series 2 3 blade 15 and 3 4 inches by 15 props so let's get aboard and find out how the sharrow props stand up to a yamaha top of the line prop the most important data for any prop is its mid rpm range performance so if you're only interested in top speed we're saving that little goodie until the end the average boat owner operates his boat about 60 percent of the time in the mid-range and for fishermen and anyone going far from the fuel docks range is the most important data point with the yamaha saltwater series 2 prop we found best cruise which we define as planing speed with the greatest range to be 4 000 rpm and 23.8 miles per hour at that speed we were burning 21.2 gallons per hour and getting 1.1 miles per gallon for a range of 282 statute miles we tested the boat from idle all the way to wide open throttle and i'll show you all the data when we compare the two props in a minute after our test we hauled the boat then we swapped the yamaha props out for the sharrow props bow weight is critical to performance particularly on a catamaran so we topped off the fuel and had the same three people aboard testing the cheryl props sharrow props are made for every specific boat in engine application and are different from one application to another the 15 and a half by 15.4 inch shell prop suite tester were made specifically for a 325 dc world cat with twin 300 horsepower yamaha engines we found the shero props best cruise to be at 3 000 rpm with a boat with 21.7 miles per hour burned 14.8 gallons per hour and got 1.5 miles per gallon for a range of 368 statute miles now let's compare best cruise speed data for both props and it's here where we find a remarkable contrast of performance first we note that the cheryl props most economical rpm is a full 1 000 rpm less than yamahas but it's 2.1 miles per hour slower the share was burned 6.4 gallons per hour less at their best cruise compared to the yamaha and this is one big critical difference this huge decrease in fuel consumption means the boat can go 1.5 miles per gallon or 36 percent farther on a gallon of fuel than can the standard prop by being significantly more efficient at best cruise the worldcat 320 with cheryl props could travel 86 statute miles farther than with the standard props for fishermen going out to the canyons and back that 86 miles can make a big difference now when we take all of our test data for both props and plot them on a graph here's what it looks like in all of our charts the blue line is the cheryl prop and the orange line is the standard prop at idle the sharrow prop is 24 percent more fuel efficient and while you think that you may not run the boat much at idle the fact is that the international boating industry association icomia says that 40 of the average engine's duty cycle is at idle so that increase in fuel efficiency of 24 can add up the next thing that becomes obvious is that at 10 miles per hour in this graph something dramatic happens note that the fuel efficiency of the saltwater 2 prop plummets precipitously to just .8 statute miles per gallon that's because the boat is trying to get over its bow waves and just isn't able to deliver to the water the torque needed to do it at 2500 rpm on the other hand the sheryl props at this rpm are now approaching peak efficiency getting 1.4 miles per gallon 75 percent more miles per gallon the boat with cheryl props attained planing speed at 16 miles per hour the cheryl prop allows the boat to plane at a lower rpm burning much less fuel in the 20 to 25 mile range the sheryl props keep their 36 percent mile per gallon average and it's not until over 30 miles per hour that the gap narrows at 35 miles per hour the efficiency of the two props is about the same so boaters running the 325 dc world cat at or near wide open throttle will get about the same miles per gallon with both props most boat buyers want to know what the top speed of a boat is even though they almost never run the boat there so let's start at wide open throttle with the yamaha props we reach the top speed of 41.6 miles per hour top speed of the boat with the sharrow was 42 miles per hour at 5 500 rpm or 0.4 miles per hour faster when we compare top speed for both props the difference is not much but it's pretty impressive for a prop that also shellacks the standard prop in the mid-range of fuel efficiency historically props have been designed to either be fuel efficient in the mid-range or fast but not both unless it's a conscious compromise the cheryl prop gives the owners the best of both worlds without compromising speed for efficiency as can be seen in this graph the cheryl prop is faster across the entire rpm range from idle to wide open throttle in a critical mid-range where most operators travel from three thousand to forty five hundred the sheryl prop is from fifteen percent to one hundred and five percent faster now let's take a look at hall shot times determining when a boat actually gets on plane is an inexact science with a monohull but with a catamaran it's even more difficult to pinpoint for that reason we'll just look at the time to attain three speed gates the sheryl props out perform the standard props at hole shots at every speed so let's summarize our comparison tested the yamaha saltwater series 2 props versus the new sheryl props tested when i got back to my office after the test and carefully looked over the data i realized that sheryl prop checked all of the boxes solidly on plane at 3000 rpm faster at all rpm 15 to 33 percent faster from 3500 to 4500 rpm 30 percent greater range but some of the cheryl props attributes are hard to measure empirically but she definitely has much greater thrust in reverse making the boat easier to dock there is noticeably less vibration at cruising speeds and there was superior handling in tight turns at high speed now let me hasten to point out that there's nothing wrong with the yamaha saltwater series 2 prop any more than there was a problem with the standard prop brands we tested two years ago the sharrow's performance superiority has nothing to do with brand geometry or maker it's simply new technology versus old technology for another analogy think of when the railroads in the 1950s moved from steam locomotives to diesel ones the steam engine certainly worked but they've been around for 130 years and the new diesel technology was simply better so the question that everyone is naturally asking is how is it that a propeller invented by a young man who was an executive producer and director in philadelphia with no engineering background was able to invent a new prop design that is dramatically better than what the greatest minds and engineers in the prop world were able to create in the last 100 years it turns out that greg cheryl in a former life was trying to solve a noise problem caused by the blades on drones that he was using to take videos of an orchestra in a theater some basic reading pointed to the phenomenon called propeller tip vortices if you've ever heard of a helicopter's whap whap whap you know how noisy this can be the helicopter in high humidity day illustrates the vortices which cause the noise the same thing happens on prop planes the same thing happens on propellers underwater prop vortices are the same and instead of creating noise they create drag which slows the prop the genius of greg sharrow was in getting rid of the blade tips by creating a loop that in the case of the drone eliminated noise and in the case of boat props virtually eliminates drag years of tank testing at the university of michigan proved that cheryl's loop prop design performed much better than conventional marine props cheryl called in some of the most prominent propeller engineers in the country to help him develop his concept over the course of 10 years of development these experts realized that the loop prop design had a second attribute that was even more important than eliminating the blade tip vortices and that was its advance rate through the water was significantly better than conventional props but that aspect of the cheryl's secret sauce will have to wait for our next cheryl video which will be coming soon in the meantime in case you're wondering greg sharrow has founded three different boundaries to cast his props and says he's planning on making 10 000 props next year further he tells us that the prop design we tested in this video is available specifically for yamaha 300 horsepower engines to find out more go to cherylmarine.com for protest.com i'm captain steve we'll see you on the water

Channel: BoatTEST.com

Views: 933,025

Keywords: boattest, boattest.com, sharrow marine, sharrow engineering, sharrow propeller, boat propeller, propeller, review video

Id: MNnB_50Z20I

Length: 11min 8sec (668 seconds)

Published: Tue Dec 28 2021

Reddit Comments

[u/HanzeeDent86]

It's so funny the people on here who think the target market for these gives a flying FUCK about the price. You guys ever price out a 5 blade cleaver prop?

These offer fuel savings to those guys who run big HP quds or quints where the astronomical fuel cost outweighs the cost of these upfront for the savings they provide. It's a business decision.

[u/username45031]

It would be a lot more convincing if the “review” didn’t sound like a press release and if the product was actually shipping.

The predicted price is ludicrous too; the design may be brilliant and performance amazing but it’s an order of magnitude more expensive. I can get a whole damn boat for $5k. Is it worth it to the guys with 4x 400hp? Maybe?

[u/--2loves--]

Are they rebuild able?

the way fuel is going, could become mainstream.