Excerpts of Letters received from 4-Blade Owners

(Complete letters available upon request)

BENETEAU 473 – 76 hp YANMAR (Purchased 4-blade DF 107)

Appreciate the tips on the pitch adjustment. Have experienced some prop-walk and will adjust at haul-out. Overall extremely satisfied. Glad we requested the “VARI” vs. competitors

-- DC. New Boat

BREWER 42 – 67hp PERKINS SABRE M65 (Purchased 4-blade DF112)

We hauled Kiyomi out and installed the new four-bladed VariProp a few weeks ago. Shortly thereafter we made a week long trip into the Delta and put about twenty-five hours on the new system. So far we’re pleased with the results. The factory had the settings right on the money: we get 2630 rpms at full throttle. I took her out last week when we had a flat day with slack water and gave her a complete rpm/speed run at all engine speeds and have charted it. I’m getting 7.7 knots at full speed; that’s 1.3 knots faster than with the old engine and prop. With the VariProp I can stop from 5.5 knots in less than a boat length. This was measured by reversing when our bow came abreast of a piling at slack water. I did it twice to confirm, and this wasn’t even at full throttle! The four blades do indeed grab some water. Remember we weigh 34,000# plus. Stopping that in less than 40 feet is impressive. I still notice prop walk in reverse, but the boat gains speed much more quickly now, allowing the rudder to compensate much faster than before. All in all, I guess you could say I’m very pleased.

-- CM. Previous prop: 3-blade fixed

BRISTOL 35.5 – 34.9hp YANMAR 3JH (Purchased 4-blade DF80)

The boat was lightly used last year. However, we did find a noticeable overall improvement in the boat’s performance. Under power, your pitch calculations were right on; in forward you predicted a speed of 6.9 kts. We actually did 7.1 kts at max rpms. With the increase in prop diameter, proper pitch, and going to four blades, we had significantly more power in heavy seas and strong currents. Under sail the decrease in drag gave us between .5 to .75 kts. Handling improved most noticeably in reverse with prop walk being greatly reduced. The ability to quickly check forward speed took a little getting used to, but has relieved some anxiety in our docking and anchoring. We are very pleased with the performance.

-- KCH. Previous prop:3-blade fixed

BRUCKMANN 50 – 140 hp YANMAR 4LH-THE (Purchased 4-blade DF128)

Love the prop and performance has been nothing short of sensational!

-- RM. Previous prop: 3-blade fixed

CHEOY LEE 42 – 56 hp YANMAR 4JH3E (Purchased 4-blade DF107)

The performance of the new prop is outstanding. Your predicted top speed was right on, in fact in flat water the boat does hull speed. Stopping power is excellent. On our engine trials with the new Yanmar, we crash stopped at 5.5 kn and came to rest in about one boat length. There is virtually no noise or shudder felt when shifting from forward to reverse and no vibration when running. As far as prop walk astern, it is minimal and in fact I prefer a small amount as it assists in docking port to. Oh yes, a comfortable cruising rpm is about 2,800 rpm and speed is about 6.7 kn. The engine tops out comfortably at rated 3,600 rpm and 7.3 kn. I am very pleased with the propeller and will gladly endorse it to anyone considering purchasing one. Please feel free to use my name as a contact if anyone needs convincing of it’s merits.

RS Previous prop: 3-blade fixed.

CT-41 - 75hp YANMAR 4JH3-TE (Upgraded to 4-blade DF 107)

Things have settled down a bit now and I’d like to commend Nautilus Propeller and the Factory for the extraordinary efforts made to accomodate my situation .

I bought my 3-blade Variprop at the Toronto boat show in 2003. It was spec’d for a 45 hp Perkins 4-107 and worked very well in that application, although the engine just didn’t produce the horsepower to make much progress into a headsea. When the engine finally died after 31 years of service, I took the opportunity to upgrade to a 75hp Yanmar. Concerned about the ability of the 3-blade to absorb the additional power, I checked with you. You felt that the 18” diameter limitation (a propeller aperture concern) and changing the pitch to the maximum available would not get the job done. You also said you’d contact the factory for their analysis and call me back.

Shortly thereafter you did call back with the factory’s data to the effect that with 75hp applied to it, my propeller would be running at 152% of design load, and would badly cavitate. You recommended against using it, but in the same breath offered a solution.

I was expecting to be encouraged to buy a bigger prop for probably $5,000.- Imagine my surprise at your suggestion that the factory would take back my 3-blade, exchange the hub for a 4-blade unit, re-use the internal mechanics and my 3-blades plus one new one, and deliver to me a 4-blade 18” diameter propeller that was perfectly matched to the Yanmar. All for about $ 1,500.-

On top of all the above, there was considerable time constraints involved with the boat out of the water on a marine railway. The yard needed their railway back, so the prop went to Germany and back by courier, the factory even offering their bulk discount with the courier service. The work was completed in days, and we wire transferred the funds as soon as we had a total. With the factory awaiting notification of receipt of funds from their bank and the transfer lost in the banking ether somewhere, you stepped in and told them to ship the prop immediately anyway. I don’t know what risk you took in doing that for us, but it did the trick. The prop arrived promptly and we launched the same day.

You were right about the 4-blade. It is like a tug-boat under power, as well as good for an extra knot under sail. We’re extremely pleased with the prop, and even more so with the efforts made by you and the factory on our behalf. In an age where the boating public must resign themselves to be being ignored, gouged, lied to, and exploited by a greedy, uncaring industry, it is a breath of fresh air indeed to deal with an organization such as yours. Many, many thanks to you and would you please convey our appreciation to the factory as well.

-- Jeff & Dawn Haloun-Townsend, S/V Aavyi- Halifax, Nova Scotia

Endeavour 37.5

Last year I purchased a 4 blade 16 inch "Variprop" for my Endeavour 37.5 sailboat from you.  My old propeller was a 3 blade16 inch fixed blade prop. My problem was the inability to back up starboard. Not a good one to have considering the narrow slip spaces at so many yacht clubs. In addition, as my plan was to sail from Lake Champlain NY to the Bahamas, a feathering prop would be an asset, as the reduction in drag allowed my boat to sail about 1/2 a knot faster due to the reduction in friction.
I was skeptical at first, since my boat was known to have a problem in reverse. Being a member of the Endeavour Owners website, this reverse propwalk was a common point of the discussions in their forum.
 
The prop was not cheap, but the reward was quite dramatic!
 
1) I was able to install it on the hard, in less than 15 minutes.
 
2) My reverse propwalk was 90% eliminated, allowing me to back up where I wanted to go, and boat owners with long keels, definitely appreciate this luxury.
 
3) The ability to fine tune the prop was easy to do while the boat was in the water. The pitch both in forward and reverse could be adjusted independently, with only a mask and snorkle.
 
4) The vibration of the boat while motoring was dramatically reduced. The vibration of my old 3 blade fixed prop was not really an issue, but if I paid attention I noticed it. Once I replaced it with the Variprop, the vibration was eliminated. Leaving the cockpit and standing on deck it was impossible to know if the engine was operating. Definitely a nice bonus!

5) During my trip, I crossed the Gulf Stream three seperate times, and one time in seas between 10 to 15 feet. This was always done under motor, and I never experienced any cavitation.
 
6) The aftersales service I received was second to none.
 
Thanks for your help in the correct prop selection for my boat.

-- IS. Previous prop: 3-blade fixed

FREEDOM 45 – 66 hp YANMAR TURBO DIESEL (Purchased 4-blade DF107)

Just a note to let you know how happy I am with my DF-107 feathering VariProp propeller. The 18” MaxProp that was on my Freedom 45 when I bought it was pretty well worn out with very loose bearings, etc., even though it only had 1250 original hours of use. I put another hundred and fifty hours on it before replacing it, but worried constantly about it, since one blade would sometimes slip a tooth, resulting in terrible vibration. As soon as I installed the four-blade VariProp, vibration went to zero. I was also impressed with how smoothly it shifts from forward to reverse and vice versa, because of the built-in clutch arrangement, which was lacking in the MaxProp. We get 6.5 knots with only 2600 RPM and just about hull speed with 3000. The pitch change was very easy; if I had had SCUBA gear I could have done it in the water.

-- RL. Previous prop: 3-blade MaxProp

HUNTER 41 (Purchased 4-blade DF-107)

Variprop Bluewater prop

When we decided to move up from our Hunter 34 to a new Hunter 41 we were already convinced to have a Variprop installed at delivery. We had had a 3 bladed model on our old 34 and absolutely loved it. It had great power in both forward and reverse and did not give up any speed while under sail.
Jesco informed us about Variprop’s new Bluewater 4-bladed prop and explained that we would not regret the extra bite that it provided especially in rough seas.

We would not know at the time how true that would be. In early August we were returning from Sodus Bay NY to Cobourg and the weather was nasty. The winds were 25+ knots on the nose and the waves were 6+ feet with the occasional 8 footer. We could not stay another day so set out at 7am headed for Cobourg. It was not a fun day but the prop kept our speed above 5 knots most of the day. We were on the lake for 11 hours and would not have wanted to imagine how much longer it would have taken with the 3 bladed model never mind the factory standard 2-bladed fixed prop . The difference in price between the 3 bladed and 4 bladed models is small considering the benefit we gained that day on the lake. I would not have anything other than a Variprop on this boat or any future boat.

-- Dave Sutherland S/V Dog Days

HUNTER 49 (Purchased 4-blade DF-112)

As you know, we fitted a four blade DF 112 propeller to our Hunter 49’ Yacht Kaumoana in February of this year. We are extremely happy with the performance of our new prop and were pleasantly surprised in the increase in both the torque and speed through the water performance the new propeller gave us.
We also believe that the increase in power is enabling us to achieve cruising boat speed at less revolutions than previously.  This is particularly important to us as we are shortly embarking on a round the world cruise, and fuel consumption is a high priority. 

We would be pleased to update you as our journey progresses.

Regards

-- Richard Tyree

MISTRAL 33 – 20 hp BUKH (Purchased 4-blade DF 80)

I must say the builder of the boat and I both like the results of the new 4-blade VARIPROP. A great improvement from what was on the boat. At max 3000RPM we will make about 6.7 kn. We like to run at about 2500 and that will keep us going 5.7 – 6.1 kn depending on conditions. As far as reverse, WOW! This is like having anti-lock brakes. You can feel the torque and the churning below the boat as the prop is cutting deep. Just for fun I brought the boat to a stop with the main and DRS up, the wind was about 8 kn and the boat was standing still!! You could see the turbulence for about 30 feet in front of the boat. … As for prop walk, it no longer exists.

-- DK. Previous prop: 3-blade fixed

MISTRAL 33 – 20 hp BUKH (Purchased 4-blade DF 80)

I must say the builder of the boat and I both like the results of the new 4-blade VARIPROP. A great improvement from what was on the boat. At max 3000RPM we will make about 6.7 kn. We like to run at about 2500 and that will keep us going 5.7 – 6.1 kn depending on conditions. As far as reverse, WOW! This is like having anti-lock brakes. You can feel the torque and the churning below the boat as the prop is cutting deep. Just for fun I brought the boat to a stop with the main and DRS up, the wind was about 8 kn and the boat was standing still!! You could see the turbulence for about 30 feet in front of the boat. … As for prop walk, it no longer exists.

-- DK. Previous prop: 3-blade fixed

NONSUCH 36 (Purchased 4-blade DF-107)

I thought it may be helpful to you if I were to share with you my experiences with other propellers as compared to the four blade Variprop.

All of the props I have used are feathering propellers with the exception of a couple of boats which had fixed two or three blades. You had specifically asked about heavy weather performance so I will emphasize my comparisons to that end.

In no particular order:

The first is fixed two and three blades. Three blades get the top mark for heavy weather performance (two blade not so much) but at a price. The drag uunder sail is unacceptable….Period.

The next is a two blade Maxprop. This prop was the poorest performer as it was noisy and vibrated due to the fact that the blades are large and flat. This caused cavitations at higher rpms and the noise and vibration transmitted through the hull. The loss of forward boat speed in heavy weather was unacceptable as at times forward speed would come down to as low as three knots while motoring into 25 knot head winds.

The next is the Auto prop. This was a great prop if you wanted to back up. It had tremendous bite in reverse and performed very nicely in forward as long as it was fair weather. That’s where it ends. In heavy conditions this prop was scary. Until you could develop some forward speed the prop didn’t auto pitch high enough to drive the boat through the waves and even then forward speed suffered. On a couple occasions I nearly lost control of the boat. Also of note is the fact that this prop has higher drag than a flat blade feathering prop but less than a fixed blade. It did however run dead smooth and no noise from cavitations. Also of note this prop requires that the transmission be locked in forward (engine off) in order to have the blades feather. Unfortunately, most transmissions should not be locked in forward while sailing. This necessitates the installation of a shaft brake.

The next is Buoy Prop. This also is a German made flat blade feathering prop. The three blades I used was close in performance to the Variprop except that the prop walk in reverse was a pain. There was no independent adjustment for pitch in reverse. This is true for the Maxprop as well. The three blade was a little noisy but not as much as the two blade Maxprop and there was very minor vibration in the higher rpm range again due to the flat blades causing cavitations.

The four blade Variprop has been the best all round performer. The fourth blade overcomes the noise and vibration issues caused by flat blades at higher rpms and the heavy weather performance is almost as good as a three blade fixed prop but without the drag under sail. In fact I don’t think I could measure the difference.

When this thing bites the boat goes! Also with the clutch pack; shifting from forward to reverse is smooth and quiet. Unlike the Autoprop which made me think the transmission would explode every time I shifted.

I would have no hesitation recommending the four blade Variprop to anyone who is serious about performance without compromise. My opinion is the performance gain is worth the extra cost. What a brilliant piece of engineering.

A very happy sailor,

-- Bryan W. Bennett “Dovekie”. Nonsuch 36

PACIFIC SEACRAFT 34 – 30 hp YANMAR 3HM35F (Purchased 4-blade DF-107)

Took the boat out for the first time today with the Vari-prop. It performed beautifully. We increased our efficiency when cruising by a full knot -- from 6 to 7 kts.  And, the boat handled beautifully in reverse. We docked stern in on the first try.  It is a very good product -- pricey, but for my money worth every dollar.

-- EH. Previous prop: 2-blade fixe


PEARSON VANGUARD – Repower to YANMAR 3YM30 (Purchased 4-blade DF80)

The sea trials … were excellent -- both for the engine and the prop. The boat moves with tremendous power and now has reverse! We were able to move at hull speed with no problem.

-- RG. Previous prop: 2-blade fixed

SHANNON 38 – 55hp Volvo D2-55 (Purchased 4-blade DF-107)

The prop has been everything you said it would be. Much more drive in forward, quicker stopping in reverse, and a definite increase in sailing speed. So chalk me up as a satisfied customer.

-- PW. Previous prop: 3-blade fixed

SOUTHERLY 42 (Purchased 4-blade DF-107)

This is just a quick note to say how much we have appreciated the Variprop over the last 12,000 miles of sailing on our new Southerly 42 Distant Shores. I had always wanted a feathering prop but I did not know just how much it would help. Performance in light airs is dramatically improved as the blades feather - I think it gives us over 1/2 knot possibly 1 knot extra speed. But this does not compromise performance under power. We had a situation a few weeks ago where we really appreciated the 4-blades of this prop! We were sailing in behind the Abacos as a norther approached and saw winds in the 40-knot range gusting to 50. We needed to power up into the anchorage and the Variprop did the job. We were able to make 4 knots forward - motoring directly into these very strong winds. I do not think our old fixed 3-blade prop could have done that. So a big thanks to Variprop - we now have the best of both worlds - strong power in gear and very small resistance for great sailing performance.

-- Fair Winds, Paul & Sheryl Shard. SV Distant Shores

SPARKMAN & STEPHENS 47’ CUSTOM KETCH (WOOD) – YANMAR 4JHBE (Purchased 4-blade DF107)

Just wanted to let you know that the 1” pitch increase seems to have done the trick, getting us 7.5 knots at 2900RPM and 7.9 at 3500. I figure hull speed for this boat to be about 7.4 knots, so that looks good to me. We did a crash stop from full ahead and I don’t think I ever saw a sailboat stop so fast. The mechanics are very complimentary about the prop and how easy it was to adjust. Your service has been great and I expect to recommend your product whenever such a prop is desired.

-- DM. Previous prop: 3-blade fixed

YOUNG SUN 43 – 85 hp PERKINS 4.236 (Purchased 4-blade DF112)

A short note to tell you how pleased I am with the new 4-blade VARIPROP. We went up Lake Huron two weeks ago and found that 1,250 rpm gave us at least 1.5 kn greater speed than before. Full speed is increased by at least 1.5 to 2 kn with little or no vibration. Reverse is positive and powerful. Under sail we now have performance unseen before. We even sailed with our 38,000 lb full keel boat in 4 kn of wind and enjoyed 2.5 – 3 mph over the ground. In all we could not be happier. Even the prop walk though reduced is still present enough to be used in turning short or in docking.

-- RD. Previous prop: 3-blade fixed