Month: April 2023

Now that I’ve hauled our boat (1999 Catalina 320) for the winter, and having had a full season under my belt with our new EWOL 3-bladed propeller, I wanted to offer some feedback regarding our experience with the change.
Our original propeller was a fixed 3-blade Campbell Sailor, which had generally worked well for us over the past 12 seasons. The Sailor is a reasonably efficient propeller when motoring ahead in relatively smooth sea conditions. As you know, it was designed with a small blade area ratio in order to try to reduce the drag somewhat when under sail. While it likely has lower drag than a more traditional fixed-blade propeller with a larger blade area ratio, of course it cannot compete with feathering and folding propellers in that regard. Furthermore, the reduced blade area lead to a significant performance compromise under power when it came time to stopping the boat from ahead mode. In order to maintain adequate stopping distance when motoring around marinas and other crowded areas, I would need to reduce speed to an excessive degree.
We replaced the original propeller with the EWOL Orion of equal diameter, and with the help of your pitch estimating chart I think we are pretty close to the correct pitch setting on the first try. As for the overall performance of the EWOL, it has exceeded our expectations significantly. The primary reasons for the propeller change for us were to (a) shorten stopping distance which we see as a safety issue and (b) improve speed under sail in our region with predominantly light winds. In both of these areas the new EWOL propeller has performed wonderfully, and I feel confident when motoring into a marina that I have much better control of the boat. It’s hard to quantify the speed gain under sail without careful measurements, but I’m certain it is significant over the full range of sailing conditions based on observations of other boats around us. Furthermore, there was the additional benefit of improved motoring performance in waves. When motoring into a moderate to large seaway with the older propeller, the added wave resistance tended to practically stop the boat with each passing wave crest (our sailing region has shallow water, and the waves tend to be relatively small in height but very steep with a short period). The original propeller just could not generate enough thrust under those conditions and at times you could hear the propeller cavitating. The design and added blade area of the EWOL helped us to power through these conditions with less slowing.
One of my concerns about the transition from a fixed propeller to a feathering is that in normal straight ahead motoring conditions the feathering propeller would suffer a lower efficiency due to (a) the lack of twist in the blades which is needed maintain a constant pitch from hub to tip, (b) the relatively large diameter of the propeller hub and (c) the larger blade area which while helpful in heavily loaded operation can decrease efficiency under normal operation. As of now it seems like this concern was largely unwarranted, as I have not noticed any significant change in calm water powering speed or fuel consumption relative to the fixed bladed propeller. Perhaps there is some, but I suspect that even if there were it could easily be remedied with some tweaking of the pitch angle.
Lastly, I want to thank you and your colleague Ivan for the excellent service and support. You can be assured that if we were to move to a different boat, the decision to install an EWOL would be an easy one.
Kind regards,
S/V Easy Going
1999 Catalina 320

I installed the propeller this weekend. It was easy, because everything was good, the diameter of fitting, the safety nut, in short: “BRAVO”.
I followed your instructions and I put some Propspeed on the propeller before mounting it on the sail drive.
Then, once the boat was back in the water, I tested the boat’s motion, the forward motion is indeed a forward motion. I have noticed a good improvement in the reverse gear, which will change me from my previous propeller.
I thank you again for your efficiency
P.J. France

Original text

J’ai installé l’hélice ce week end . Cela a été facile , car tout était bon , le diamétre d’emboitement , l’ecrou de sécurité , bref : ” BRAVO ” .
J’ai suivi vos indications et j’ai passé du Propspeed sur l’hélice avant de la monter sur le sail drive.
Ensuite une fois le bateau remis à l’eau j’ai testé la marche du bateau , la marche avant est bien une marche avant. Pour la marche arrière j’ai bien constaté une bonne amélioration , cela va me changer de ma précédente hélice.
Je vous remercie encore pour votre efficacité
P.J. France

So, after my trip to Maine last week I now have 30 hours under engine with the prop. First impression was wow, what a lot of thrust. The boat accelerates well and stops fast. It is great to have the thrust to kick the stern around quickly in tight corners and push the bow up into the wind. It has made the boat more responsive and controllable. I did not alter the pitch setting. It is a fast propeller. In flat water, I am now cruising at 6.5 knots at 1700rpm; with the fixed prop, we were doing 6 knots at 2000rpm. At 2500rpm we achieve over 8 knots – I never saw more than 6.8knots with the old propeller. With 15 knot head wind and seas, performance is not affected very much – we still do 6 knots at 1700rpm. So now we never cruise at more than 17-1800rpm, as I am happy to motor at 6-6.5 knots and have the extra power in reserve. There is less vibration.

I have not yet done any fuel consumption calculations, as we were away from marinas and topped up the tank with a jerrycan. With the 2 blade fixed propeller, we were using a about a gallon per hour at 6 knots. I look forward to seeing what we achieve with the new prop.

Sailing performance is excellent. The prop feathers instantly and there is no need to lock the transmission off, though I still do so out of habit.

So, in short, I am most impressed with the EWOL performance. In mid-October we start our journey from Boston to Florida and I am very happy this propeller will be on the boat.

P.N. USA