Sharrow boat propellers

[Donald]

Has anyone considered getting propellers from this company? Highly engineered and better performance.

The propellers for my VP DuoProp would be $8800 for the pair and delivery date is 2026. Or around that.

I think VP OEM propellers would be around $2000 for a pair.

The VP DuoProp has an inner and outer prop.

 

[wings&wheels]

I did a lot of research and decided that the ROI just is not there for us. Maybe if I was running at cruise to the Canyons a few times a week, but for typical recreational use, they do not make sense.

One other concern, if you have twins like us, is the availability of a replacement if you have a problem. Would not wat to have to switch both back while waiting over a season or two for a replacement. Less of an issue for you as you would probably be changing both anyway.

That said, the tech and performance appears impressive. One boat at our marina has them, but I have not me the owners yet.

 

[Donald]

I wonder if Mercruiser and VP have looked at the design. They have the design and engineering teams to implement what Sharrow is doing.

 

[alarmguy]

Face value it looks very impressive. My question may be the same as yours then, what is the catch? I can see on some of the test the very top end falls off. Also here is another question, are they comparing the results to OEM standard aluminum props or the best props offering by the OEMs in Stainless Steel
Still the results are impressive, I just want to know how impressive when compared to the best that the OEMs offer.

https://sharrowmarine.com/blogs/performance-reports

I also wonder in the engine at those higher speeds and lower RPMs are loading the engine in a way the engine maker wasn't designing for? Meaning both props will deliver the same top end but in this case the Sharrow at lower RPMs with a lower HP engine in the lower RPM range is that unduly loading the engine.

 

[RTexasF]

The midrange decrease in gallons per hour is impressive as is the lower RPM required to plane. With fuel savings, I can see where a fishing guide or other commercial user could get their investment back easily over time. As far as the average Joe the pricing vs the advantages just doesn't work.

 

[alarmguy]

The midrange decrease in gallons per hour is impressive as is the lower RPM required to plane. With fuel savings, I can see where a fishing guide or other commercial user could get their investment back easily over time. As far as the average Joe the pricing vs the advantages just doesn't work.

Yes and I still want to know what they consider "traditional" I suspect that might be aluminum in some or all cases since stainless OEM many times is an option.
I mean why dont they list the details of the "traditional" props?

Also the OP has an I/O but all the tests are done on Outboards, completely different animals. Why not some comparisons on I/O's ?

Im not doubting that they are good props but to spend that money it would be nice to see the proof. One thing for sure I am sure the design is patented but I dont know. I still suspect their maybe tradeoffs and still need to see data for I/O's
Maybe it is possible the tradeoff is just cost of manufacturing the product. After all in boat test reports top end is still the same or better on OEMs

 

[Kira]

Impressive.
At $4,400 each, I was expecting something 'fancy' like counter-rotating props, not a single piece prop.
Does anybody know how much design time / T&E / testing was involved?

It seems they're priced in accordance with fuel savings. Using the video example of saving ~$40/hour (at cruising speeds), these props, if the same as the OP's at $6,800 PREMIUM/pr., would break even at ~170 hours and do it more smoothly.

Since the design is now settled, why the long delay for delivery? It's still a single lump of metal.
Maybe there's only one shop making these?
Anybody know how effective patent enforcement is on the high seas?

Also: In the video, a guy is shown swapping props with a cordless tool and deep socket. Easy.
Do those center nuts and the prop-to-spline contact length always slide off so cooperatively?

 

[Mainia]

Impressive.
At $4,400 each, I was expecting something 'fancy' like counter-rotating props, not a single piece prop.
Does anybody know how much design time / T&E / testing was involved?

It seems they're priced in accordance with fuel savings. Using the video example of saving ~$40/hour (at cruising speeds), these props, if the same as the OP's at $6,800 PREMIUM/pr., would break even at ~170 hours and do it more smoothly.

Since the design is now settled, why the long delay for delivery? It's still a single lump of metal.
Maybe there's only one shop making these?
Anybody know how effective patent enforcement is on the high seas?

Also: In the video, a guy is shown swapping props with a cordless tool and deep socket. Easy.
Do those center nuts and the prop-to-spline contact length always slide off so cooperatively?

It is 100% CNC cut from a block of stainless from a company I saw making them. I don't know if this is the same company or another. I don't know if anyone is using stainless castings yet or if the strength issue leads the prop to only be made out of a big block of stainless.

My main concern would be what happens if you get a micro hit where a conventional prop still technically is somewhat usable, where this prop would be a piece of junk. Not like you can throw it on a blade block and massage it and re-blueprint it.

 

[RTexasF]

Yes and I still want to know what they consider "traditional" I suspect that might be aluminum in some or all cases since stainless OEM many times is an option.

There are multiple tests on YouTube. In every case, the Sharrow was tested against the manufacturer's stainless prop{s}.

 

[alarmguy]

..

Also: In the video, a guy is shown swapping props with a cordless tool and deep socket. Easy.
Do those center nuts and the prop-to-spline contact length always slide off so cooperatively?

Yes, always, unless of course a neglected boat that doesnt under go proper yearly maintenance it can become a problem.

Actually with Volvo Penta outdrives you remove the prop every year as it's the only way to change the gear oil.
But even with Merc, part or maintenance is to remove the prop every year, re-coat the spline with anticorrosion grease. Props slide right on and off with zero effort. If maintenance is ignored for a few years, this can become an issue for a boat stored in salt water.

It's pretty amazing, in this case our VP outdrive, 2 weeks ago (or less) I changed the gear oil. When putting the prop back on, you snug up the prop nut then back off and finger tight is all it is. Then locknut with cotter pin. Thanks for reminding me, I need a new pin, only one side of it left

I still want to see actual tests on these props compared to top of the line OEM props. Those comparison charts do not disclose what the "traditional prop" is. I suspect since they say "traditional" that means standard OEM prop, many times made of aluminum, yet the OEMs also make optional high end props. I suspect those props are not the ones they are comparing.

 

[UncleDave]

The marine industry has been watching this for a while now.

There is no magic here.

Its performance is most often compared to a "factory" 3 blade SS prop. Hardly an optimal design.

It's relatively easy to reduce slippage in the midrange of any boat by simply increasing the number of blade surfaces to 4, 5, or 6. which is what a sharrow is - a prop with 6 blade surfaces.

They just happened to be connected vs. open which necessitates a CNC machine where a regular 4, 5, or 6 blade can be molded and made much less expensively. Slip is an interesting thing - sometimes you want some of it, sometimes you dont.

The "catch" more blade surfaces = more drag on the top end - to compensate you need to thin them out - a lot. This gets expensive and compromises life. Seriously (for money) high performance designs dont run fully submerged, but partially out of the water.

4,5, and 6 blade CNC milled props have been available for a while and are correspondingly expensive. 7-10K a prop isnt unusual at all.


How much sense does this expense make on a recreational pleasure boat? Not much.

 

[DriveHard]

Quote

The marine industry has been watching this for a while now.

There is no magic here.

Its performance is most often compared to a "factory" 3 blade SS prop. Hardly an optimal design.

It's relatively easy to reduce slippage in the midrange of any boat by simply increasing the number of blade surfaces to 4, 5, or 6. which is what a sharrow is - a prop with 6 blade surfaces.

They just happened to be connected vs. open which necessitates a CNC machine where a regular 4, 5, or 6 blade can be forged and made much less expensively. Slip is an interesting thing - sometimes you want some of it, sometimes you dont.
The "catch" more blade surfaces = more drag on the top end - to compensate you need to thin them out - a lot. This gets expensive and compromises life.

4,5, and 6 blade CNC milled props have been available for a while and are correspondingly expensive. 7-10K a prop isnt unusual at all.


How much sense does this expense make on a recreational pleasure boat? Not much.

View attachment 237611View attachment 237612

I tend to agree here...

I dug into it a bit, including watching all three episodes of this propeller efficiency test. Guess which style won (hint...it isn't the one being discussed).


This kind of reminds me of those claimed 100 mpg fixes for cars...you don't get something for nothing. If it was true, all the OEM's would be clambering for that tech.

I would test one on my Volvo Penta DP if it was given to me...not sure I would buy it even if it was the same price as the OEM prop with my own money.

 

[UncleDave]

Quote


I tend to agree here...

I dug into it a bit, including watching all three episodes of this propeller efficiency test. Guess which style won (hint...it isn't the one being discussed).


This kind of reminds me of those claimed 100 mpg fixes for cars...you don't get something for nothing. If it was true, all the OEM's would be clambering for that tech.

I would test one on my Volvo Penta DP if it was given to me...not sure I would buy it even if it was the same price as the OEM prop with my own money.

I'd rather have multiple different size high quality props than one set of these.

 

[alarmguy]

The marine industry has been watching this for a while now.

There is no magic here.

Its performance is most often compared to a "factory" 3 blade SS prop. Hardly an optimal design.

It's relatively easy to reduce slippage in the midrange of any boat by simply increasing the number of blade surfaces to 4, 5, or 6. which is what a sharrow is - a prop with 6 blade surfaces.

They just happened to be connected vs. open which necessitates a CNC machine where a regular 4, 5, or 6 blade can be molded and made much less expensively. Slip is an interesting thing - sometimes you want some of it, sometimes you dont.

The "catch" more blade surfaces = more drag on the top end - to compensate you need to thin them out - a lot. This gets expensive and compromises life. Seriously (for money) high performance designs dont run fully submerged, but partially out of the water.

4,5, and 6 blade CNC milled props have been available for a while and are correspondingly expensive. 7-10K a prop isnt unusual at all.


How much sense does this expense make on a recreational pleasure boat? Not much.

View attachment 237611View attachment 237612

Actually they are 3 blade props
https://sharrowmarine.com/pages/video

 

[UncleDave]

Actually they are 3 blade props
https://sharrowmarine.com/pages/video

Each blade has two surfaces.

 

[alarmguy]

Each blade has two surfaces.

Yes but looks nothing like the photo you posted. Its three blades with a hole in the middle would be more accurate as it is part of one blade and perform a function. It is a 3 blade prop, as far as how it handles it designed surfaces is its science.
Actually pretty impressive engineering. *LOL* I would love to try one but that will never happen. Heck, I would be more concerned about theft!!

 

[UncleDave]

Everyone that looks at it comes to the same conclusion.

https://boattest.com/article/boattest-review-sharrow-propeller

“We were able to make hard port and starboard turns at speed without the hull sliding or fear of overturning the boat, Captain Steve said. “The boat seemed ‘glued’ to the water.” That is because of the tremendous traction the Sharrow Propeller™ gets with what amounts to six blades grabbing the water.

 

[UncleDave]

Yes but looks nothing like the photos you posted. Its three blades with a hole in the middle

Im wasnt trying to make a claim they look the same.

Im also saying if you want similar results - you can just upgrade from a 3 blade to a 4, or 5 blade prop for much less money.

I was showing what a comparably priced CNC milled prop typically looks like and how it is designed vs this sharrow.

 

[UncleDave]

I would be more concerned about theft!!

Pretty much all guys running CNC props pull them off as soon as they are out of the water for that reason and possible damage.

 

[alarmguy]

Here is how they are made