Feathering propeller on small boat

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bluemoongaffer

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I've got a small, long keel boat, rather like the Shrimper / Crabber (Golant Gaffer). I’d like to treat myself to a feathering propeller. Anybody have experience of these on this size / type of boat? Particularly if you noticed a marked improvement in sailing performance versus a two bladed fixed prop. Thanks
 
A thing to watch is whether you have enough space if the rudder is close behind the prop. I noticed that Cornish Crabbers had a Darglow Engineering Featherstream on their new 26 footer at Excel. I understand that the Featherstream was designed with limited fitting space in mind.
 
In my opinion, there would be little value for this type of vessel because water drag increases at the square of the velocity..

1 knot = 1 drag unit
2 kts = 4 drag units
3 kts = 9 drag units.

Far more rewarding on a fast sail vessel... I lose a knot from hull speed when my prop fails to feather...

If I pay attention, I catch the problem early :o:o
 
Monique Are you calling my boat slow?! I'll have you know that she can get up to 5.9 knots in the right breeze.

Actually, the Darglow Featherstream is my choice -nice people to talk to as well.
 
bluemoongaffer said:
Monique Are you calling my boat slow?! I'll have you know that she can get up to 5.9 knots in the right breeze.

Actually, the Darglow Featherstream is my choice -nice people to talk to as well.
Click to expand...

I was going to buy a 20 inch featherstream, but after talking to Chris at Darglow and checking my existing prop, which is a bit undersized, I went for the 21 inch MaxProp, also from Darglow. I found the company very helpful.
 
We had an Autoprop on our Westerly Konsort, with each blade pitching independently. Hard to tell the exact difference between that and the previous fixed 3-blade but as a ball-park, probably about a knot faster under sail. My Dad thought his Autoprop made about a knot of difference on his Excalibur. In very light winds, I think it often made the difference between maintaining steerage and stopping. I should imagine that a 3-blade featherer would be a great deal more efficient under engine than a two-blade fixed, too.
We also have a big Varioprop on our current Tradewind 35, but we've had it ever since we've had the boat, so I can't compare it. But with our experience of the Autoprop, I'd no sooner buy a fixed prop now than I'd buy a car that didn't have ABS.
 
I've just ordered a 3-bladed Featherstream for my heavy, long-keeled Vancouver 27, but as the prop isn't yet fitted I cannot report on the improvement in speed over the old 3-bladed fixed prop in light to moderate winds. (Obviously, reefed down in a F5-6 with plenty of power in the rig, I wouldn't expect drag to be any real issue.)

As to price, Darglow are happy to give a reasonable discount on the full price for a prop ordered now (busiest period) but to be made and delivered later in the Spring (when they're less busy), which will help take the sting out of the cost.

One other point to note. A friend with a Victoria 26 (long-keel double-ender) has a fixed 2-bladed prop. When under sail, he locks it in the up-and-down position to reduce drag - when it is effectively in the 'lee' of the long keel. (I think he knows when its in this position, because it corresponds to the flywheel TDC mark being in a certain position itself.)
 
bluemoongaffer said:
Monique Are you calling my boat slow?! I'll have you know that she can get up to 5.9 knots in the right breeze.

Actually, the Darglow Featherstream is my choice -nice people to talk to as well.
Click to expand...
:o:o:o Ooops, I did not expect your vessel to be that quick. Was not meant as an insult... just a thought.

FWIW, I have a Maxprop and it works very well. No space constraints.

Cheers,
 
We replaced the two blade fixed prop on our Westerly Storm with a three blade Featherstream for last season and I reckon we have gained the best part of a knot under sail. We found that the feathering prop required a change in throttle technique when manoeuvring under power and switching between forward and astern, involving a slight pause while the blades realign and then feeding in the power very smoothly after you feel the prop start to bite. Other than that, an excellent product and -- as already been said -- the Darglow people are really helpful and friendly.
 
I have a problem that I only have a 3/4 inch shaft on my boat. I wanted a Bruntons Autoprop but they (and seemingly everyone else) won't touch anything under a 1in shaft..... Except for Darglow as you've already found. Very helpful but extremely expensive I thought. They too offered me a featherstream or a maxprop......... the maxprop being able to be repitched by taking it apart and the featherstream requires a new insert to be machined for every repitch. They supply you with one repitch FOC when you buy the prop though.
 
Monique said:
In my opinion, there would be little value for this type of vessel because water drag increases at the square of the velocity..

1 knot = 1 drag unit
2 kts = 4 drag units
3 kts = 9 drag units.

Far more rewarding on a fast sail vessel... I lose a knot from hull speed when my prop fails to feather...

If I pay attention, I catch the problem early :o:o
Click to expand...

I agree with the above in theory but not practice. I fitted a Featherstream last winter and now find we sail when we used to motor. BIG difference at low speed but not as much at higher speeds which goes against the drag theory as we should see better performance at higher speeds.

Had a 2 blader before with lots of kick when going astern and it's now much improved. Darglow are nice people to deal with and delivered on time.
 
bluemoongaffer said:
I've got a small, long keel boat, rather like the Shrimper / Crabber (Golant Gaffer). ...
Click to expand...
You may find that a folding propeller is much cheaper than a feathering propeller, also that you may have trouble finding a feathering propeller suitable for a small engine. I'm told that (some) folding propellers are now OK in astern, I'll find out after my boat is launched! But of course a folder will need space behind the propeller to allow blades to fold.
 
blackbeard said:
You may find that a folding propeller is much cheaper than a feathering propeller, also that you may have trouble finding a feathering propeller suitable for a small engine. I'm told that (some) folding propellers are now OK in astern, I'll find out after my boat is launched! But of course a folder will need space behind the propeller to allow blades to fold.
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Prop aperture on a long keeler is very unlikely to have space for a folder, surely. A feathering prop will barely get "longer" upon acting, and even then possibly not beyond the hub, whereas a folder (or autoprop) will extend astern, and foul with the rudder.
 
Or...

This a loony digression away from an interesting and useful thread, but...

...has anyone ever considered some form of jet-drive, on a sailboat? Like a fore-and-aft version of a bow thruster, with rather more kick. It'd eliminate drag and there'd be no more danger of prop-fouling.

I'll dream on... :rolleyes:
 
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