Shadow prop best ever or faff ?

[simonfraser]

Sharrow prop video inc boat test .com review

 

[Mr Googler]

You’ll buy one ??

 

[ontheplane]

It does look amazing - seen many tests of it now - but machined from a single slab of stainless and costing well over £1800 per prop I think it’s a big ask....

 

[burgundyben]

Its been around for years yet nobody has them, what does that say?

 

[ontheplane]

Too dear - simples

 

[ChromeDome]

If so good on efficiency, has anybody seen it on a commercial vessel?
Or a shaft driven pleasure boat?

 

[QBhoy]

The 3 tests they’ve carried out so far have been ridiculous. Wish they would do a proper comparison. This latest one is the most ridiculous of them all. Comparing to a 5 blade is just silly. A 5 blade is simply the least efficient and slowest prop available off the shelf too.
but worse than that…me being a prop geek…I ran the prop slip numbers for their results…
The 5 blade numbers show nearly 30% prop slip (just unheard of to be that poor. Average would be 10-15 for normal boat, give or take.
But the numbers for the sharrow they published show this test for what it is..laughable and insulting.
The average top speed numbers quoted show a prop slip of 0%, an impossible number. Meaning the higher of the top speed figure puts the prop slip into negative numbers…also impossible.
Kidding themselves on. Should be ashamed of themselves here.

 

[burgundyben]

Totally agree.

I'd love to see a full side by side CFD comparison.

I know what it would show.

 

[ontheplane]

I think it probably is more efficient looking at the lack of vortices, however, I still wouldn’t pay £1800 for a prop I could clout on the bottom 1st time out.....

But so hard to see past the obvious sponsorship I’m afraid