Sharrow Props

[Remedy2]

I have a 2022 C288 with dual Y250s. They are thirsty boys and currently seeing 22gph consumption at 4000 RPM- usually puts me at 30mph.

I've looked at the Sharrow's and they intrigue me as it will increase fuel efficiency ~16% based on similar boats. I plugged that into AI and asked what the ROI would be based on $10k (5k each), $5.50 per gallon gas and ~120 hours per year. It would take me four years to recognize the ROI. Based on previous experience and looking into the future I plan on keeping this boat well past four years.

The other benefit that is SUPER intriguing is the noise reduction: it is significant. This video is mind blowing: https://www.youtube.com/watch?v=b9a40Rs5CxE

I haven't seen anyone post results of putting Sharrow's on- any feedback is appreciated.

https://sharrowmarine.com/

 

[Submariner]

I'm doing extensive prop testing on an RT27-OB with a Yamaha F300. I'm working directly with PowerTech propellers. I've tested several prototypes and have detailed graphs of mpg vs gph vs mph of each test.

The current 5 blade prototype prop I've got on my boat is close to the Sharrow in terms of mpg and overall performance. Personally, I say it's "good enough for most", but PowerTech says they can do better, testing continues.

5 blades are balanced, quiet. Provides improved hole shot, fantastic mid-range cruising (3000-4000 RPM at 11-19mph), and fantastic reverse thrust which aides in docking.

I initially reached out to PowerTech back in January to see what could be done with a conventional prop that costs less than $1k. Once we (PowerTech and I) get it dialed in, we'll publish the spec's for folks to decide what's best for them.

I have performance numbers on a RT27-OB F300 with a Sharrow, Yamaha 3 blade, PowerTech 4 blade (2 versions), and a PowerTech 5 blade (2 versions).

 

[emtlibby]

I'd buy one of those PowerTech props in a heartbeat if it works out. Ive done the math on the Sharrow, I may eventually break even, but I am not paying that premium...

Submariner, are these 5 bladed props available now, unoptimized?

 

[Rocky Lou]

I'm running Sharrow props. Unlikely you'll read very much user feedback about them because many of us were required to sign NDAs. I probably said too much already.

 

[Rebel112r]

I have a Sharrow. No NDA! I paid for the prop. With your NDA, did you buy outright or are you testing, and maybe buying? They have never said a word to me about what I can say about their props. FWIW

 

[Rocky Lou]

I have a Sharrow. No NDA! I paid for the prop. With your NDA, did you buy outright or are you testing, and maybe buying? They have never said a word to me about what I can say about their props. FWIW

I tend to take NDAs perhaps too seriously. The only comment I can make is that I have had Sharrow props for roughly 3 years.

I would love to see RT and CW posted reports on https://sharrowmarine.com/blogs/performance-reports?page=1

In my opinion, the R27 is the most 'standard' type hull of FM boats and would likely perform well. However, I have not seen any comparison reporting. I don't think it's a coincidence that the R27 is one of the few that still shows a Performance Report on the website. The report for my boat was removed.

 

[Submariner]

I'm running Sharrow props. Unlikely you'll read very much user feedback about them because many of us were required to sign NDAs. I probably said too much already.

Sorry, but I just don't get that... NDA to buy a prop? They don't want you talking about it?

 

[Submariner]

I'd buy one of those PowerTech props in a heartbeat if it works out. Ive done the math on the Sharrow, I may eventually break even, but I am not paying that premium...

Submariner, are these 5 bladed props available now, unoptimized?

The unmodified versions are available today. I don't think they normally stock 5 blade prop's. They make them when they're ordered. However, the modification does offer a boost in mpg efficiency in the mid-range.

It's been a fantastic experience working with PowerTech. They know what they're doing.

 

[Ed604]

I am interested in what is being discussed here. I have the same boat as Rocky Lou and would like to see how I might be able to hold plane at a lower RPM (read better MPG) than I currently am and, as well, I would really like to be able to have more thrust in reverse.
Yes there are twin engines but the idea that you "split the sticks" isn't really in the cards for these boats in anything other than dead flat water.
The engines are so close together for one and also, I imagine the steps in the Hull limit the effectiveness of the thrust generated when reversing?
You sometimes have to apply some generous throttle to get the boat to respond when backing.

Submariner I would wonder if the effectiveness of the 5 blades would help with stern lift and going a bit faster at lower RPM's?
I will keep an eye on what you Gent's are doing here for sure!
thanks for sharing!

Rocky Lou....its too bad that Sharrow won't allow you to share with other cutwater owners who might also want "better Props" it is quite odd that they won't want the public disseminating their products?

happy to read the thread,
Ed604

 

[Submariner]

In my opinion, the R27 is the most 'standard' type hull of FM boats and would likely perform well. However, I have not seen any comparison reporting. I don't think it's a coincidence that the R27 is one of the few that still shows a Performance Report on the website. The report for my boat was removed.

I have a pretty good graph of a Sharrow MX 15.68x15 on an RT27-OB (gph, mpg, mph).
Two friends of mine have one on their R27-OB. It'll peak around 2.0 mpg cruising... Blending slow boat, cruising, no wake zones, wind and current on a trip across the San Juan Islands and Puget Sound, expect about 1.8mpg averaged on a Sharrow on R27-OB (90 miles'ish).

I've got comparison graphs of the Sharrow, Yamaha, and PowerTech prop's that I've tested.

 

[Submariner]

I am interested in what is being discussed here. I have the same boat as Rocky Lou and would like to see how I might be able to hold plane at a lower RPM (read better MPG) than I currently am and, as well, I would really like to be able to have more thrust in reverse.

Submariner I would wonder if the effectiveness of the 5 blades would help with stern lift and going a bit faster at lower RPM's?
I will keep an eye on what you Gent's are doing here for sure!
thanks for sharing!

PowerTech gave me a 4 blade and a 5 blade, both are modified prop's. The modification they're doing improves the mid-range (3000-4000 RPM) by 10-20%. This makes the MPG curve really flat. From 11mph - 30mph is pretty much the same mpg. The Sharrow also has this characteristic.

The 5 blade prop (and the 4 blade prop) I've tested, are specifically designed for stern lift.

As I drive around testing the 5 blade modified, I vary my speed based on the sea conditions. Flat seas, I'm doing 28mph at 1.6mpg. The seas kick up and all of a sudden I'm in 2 footers and the ride is uncomfortable, I slow down to 17mph, and keep 1.6mpg. I can cruise on plane down to 11mph while retaining fuel efficiency.

We went from Everett to Port Ludlow a couple weeks ago with the Everett Yacht Club. Mukelteo down to Possession Bar, across Puget Sound over to Point no Point... 2-3 foot seas the entire way. I slowed down to 11-12 mph and stayed on plane. Fuel efficiency was around 1.45mpg as we were tossed around. But the ride was more comfortable and it kept the sea water off my windows. Once we got to Point no Point, I had shelter from the wind, seas got flatter and I was back up to 33mph. The 30 mile trip I averaged a little better than 1.5mpg. It took us 2 hours. Two days later we came home. Port Ludlow to Everett in what was near perfect conditions. 30 miles, we were home in an hour, and I averaged 1.70mpg dock to dock.

In comparison, the Yamaha 3 blade OEM prop... 57 miles (Tacoma to Everett) in near perfect conditions and I averaged 1.61mpg dock to dock.

I've got over 400 hours running the OFS4 PowerTech prop. The 5 blade is better than their OFS4 on the RT27-OB without question. The extra blades balance the prop (less noise, smoother operation), reverse thrust is greatly improved which makes docking easier. Hole shot is improved a lot (pops up on plane quick!), mid-range is amazing and fuel efficiency is improved. Steering to port and starboard is easy with the 5 blade. I can operate my boat on plane between 11 and 33mph and be anywhere in between 1.5 and 1.74 mpg, with an average for the trip of about 1.6. WOT is 5650 RPM at 36mph at 1.33mpg.

The RT27-OB is greatly affected by wind. 15+ knots of gusts will show itself at the fuel dock as opposed to calm(er) conditions.

 

[Remedy2]

Man this thread turned a direction I didn't see coming! Reading between the lines and straight out advice:

1. Sharrow's performance numbers aren't as advertised. The fact they took down the performance report is concerning. So is signing an NDA to buy a prop.

2. The Power Tech 5 blade prop seems the way to go. My only concern is you're running a single; I'm running doubles. Do they offer a 30 day "try out" or return?

 

[Rocky Lou]

1. Sharrow's performance numbers aren't as advertised. The fact they took down the performance report is concerning. So is signing an NDA to buy a prop.

- My comment on the performance report referred to the Cutwater.com site, not Sharrow. When I bought my boat, there was a posted Performance Report that was taken down.

- "Buying" a Sharrow prop does not require an NDA according to Martin.

 

[Remedy2]

1. Sharrow's performance numbers aren't as advertised. The fact they took down the performance report is concerning. So is signing an NDA to buy a prop.

- My comment on the performance report referred to the Cutwater.com site, not Sharrow. When I bought my boat, there was a posted Performance Report that was taken down.

- "Buying" a Sharrow prop does not require an NDA according to Martin.

Your 302 is the closest to my 288- I may give PowerTech a call today and see what they say.

 

[Edmund]

1. Sharrow's performance numbers aren't as advertised. The fact they took down the performance report is concerning. So is signing an NDA to buy a prop.

- My comment on the performance report referred to the Cutwater.com site, not Sharrow. When I bought my boat, there was a posted Performance Report that was taken down.

- "Buying" a Sharrow prop does not require an NDA according to Martin.

Your 302 is the closest to my 288- I may give PowerTech a call today and see what they say.

Did you work with PropGod (Ken) with PowerTech or someone else? I repropped my C24 with a PowerTech 4 blade and made it a simply better boat.

 

[Ed604]

This is quite interesting! I guess the five blades get enough grip that some of the benefits that the sharrow are using their new prop to create, are also achievable with just more blades from a traditional style? And, for a lot less than 5k per prop I imagine!

I wonder if there are any further stabilizing that happens with the additional grip? I find my boat fairly sensitive to trim not as bad as a past 8ft 6inch aluminum hull mind you, but not quite as "planted" as other comparable 10ft boats. Speed wise I am totally willing to give up some top end as I really don't need to do 53 miles an hour on the top end?

I will be considering this 5 blade option carefully.

thanks again for sharing!

Ed604

 

[JunieBird]

Following, We have the C-288 and are a solid 1.4mpg avg. Hole shot/stern lift is adequate/not a concern. It wants to hop up on plane pretty quickly. Improving range would be nice...
JB

 

[Rocky Lou]

Following, We have the C-288 and are a solid 1.4mpg avg. Hole shot/stern lift is adequate/not a concern. It wants to hop up on plane pretty quickly. Improving range would be nice...
JB

There are separate interests in this thread that are: improving performance vs. overcoming a non performant hull.

Fuel economy for both R27s and C288 (1.4MPG from JunieBird) reflect, what I consider to be, performant hulls and a desire to do even better.

Looking at C302/32 that get 0.7 MPG or worse reflect hull design issues and non-performance. For example, when I compare my boat to my brother's GW Express 330 that is much heavier and Beam Amidships: 11'7" (3.53 m); Center Line Length w/o Engines; 33'6" (10.21 m), I see him getting a solid 1.2 MPG with similar power. Clearly, something is wrong.

 

[Edmund]

Following, We have the C-288 and are a solid 1.4mpg avg. Hole shot/stern lift is adequate/not a concern. It wants to hop up on plane pretty quickly. Improving range would be nice...
JB

There are separate interests in this thread that are: improving performance vs. overcoming a non performant hull.

Fuel economy for both R27s and C288 (1.4MPG from JunieBird) reflect, what I consider to be, performant hulls and a desire to do even better.

Looking at C302/32 that get 0.7 MPG or worse reflect hull design issues and non-performance. For example, when I compare my boat to my brother's GW Express 330 that is much heavier and Beam Amidships: 11'7" (3.53 m); Center Line Length w/o Engines; 33'6" (10.21 m), I see him getting a solid 1.2 MPG with similar power. Clearly, something is wrong.

Almost sounds like your NDA is keeping you from a disappointing Sharrow assessment

 

[Submariner]

Following, We have the C-288 and are a solid 1.4mpg avg. Hole shot/stern lift is adequate/not a concern. It wants to hop up on plane pretty quickly. Improving range would be nice...
JB

There are separate interests in this thread that are: improving performance vs. overcoming a non performant hull.

Fuel economy for both R27s and C288 (1.4MPG from JunieBird) reflect, what I consider to be, performant hulls and a desire to do even better.

Looking at C302/32 that get 0.7 MPG or worse reflect hull design issues and non-performance. For example, when I compare my boat to my brother's GW Express 330 that is much heavier and Beam Amidships: 11'7" (3.53 m); Center Line Length w/o Engines; 33'6" (10.21 m), I see him getting a solid 1.2 MPG with similar power. Clearly, something is wrong.

Could also be the engine height on where your twins are mounted on the transom. Just a thought.