Just ordered a power thruster

[bscott]

The stern lifting that I notice is due to the more concentrated prop thrust that the Power Thruster provides. It is not designed as a lifting device. The extra thrust, especially at slow speeds with a small diameter prop, will help control the steering. especially in reverse. If you get one and don't like it--send it back

Bob

[Crikey]

Here's what the factory says about lifting hydrofoil attachmnents to the outboard motor. I'm not sure that these comments apply exactly to this type of attachment.

"Do not install a lifting hydrofoil on the cavitation plate of the outboard motor. These are airfoil shaped wings, offered in various sizes and shapes. Their purpose is to provide lift at the stern of the boat. This raises the stern and forces the bow down, allowing the boat to get up on a plane more quickly. If they do keep the boat level when coming up on a plane, the ballast tank may not drain completely when the boat is underway. You may think you have an empty tank, but you may not.
These hydrofoils create another problem when the boat turns or leans sideways while underway. The lift that they provide goes straight up the centerline of the outboard motor, adding a strong force to promote further leaning or capsize.
These devices can exert a large amount of force; enough to snap off the cavitation plate that is cast as part of the drive shaft housing. Avoid them. "

Dennis

In spite of my earlier, somewhat facetious reply I would like to add some counterpoints to Dennis's factory quotation.

There are indeed several models and makes of hydrodynamically shaped wings made for bolt on attachment to outboard cavitation plates, and user feedback has, over time, pointed to a number of catastrophic failures of the plate. I don't think this is across the board though and my impression remains that the majority of users remain unaffected and largely happy with their purchases.
Regardless, it seem to me that a horizontally oriented wing (extending straight out from the plate) would certainly grab a lot of force if water or speed conditions, as well as the boat hull type, were applied suddenly or for a long enough period. The overall transom mass of the boat in question would have a great deal to do such an event, but I think speed has to be the main culprit. In a Macgregor, I don't think either situation will stand out though the other variables, such as motor construction and horsepower can come into play. This not a cigarette (blockade runner)!
Quebec1's model is very becoming popular with many types of craft, and I think totally avoids the loadings that a straight out wing can be subject to. There is also a possibility of a poor and loosely fitted installation contributing to eventual failure but Bertrand is obviously a very thorough enthusiast, as his postings show and I don't think there will be any issues of this sort.
My own choice, while quite different still rested on the desire to obtain at least some of the benefits advertised for these kind of products. Namely, fuel economy, planing, straight line stability and better directed thrust. I chose a bolt free design partially from paranoia but mainly because I liked some other aspects of their engineering. As a result I have my own concerns about it falling off the motor and am attemting to adress this before hitting the water. Time will tell - and you'll hear it here first!
The other remaining point concerning operation with a partially emptied ballast, as we should all know, is well taken. I think everyone does the 'double check' before closing that valve. I can't see too obvious a connection between hydrofoils and inattention. You would think a similar condition would occur if the draining operation was carried out at speed with a 90hp engine leveling the hull and there are some dealers fitting out new Macgregors with engines of this capability while neglecting to reference problems of this potential in their literature. In either case, true or otherwise, a reduction of speed during draining easily returns the 'bow high' position and should put to rest whether proper drainage has occurred. Very poor loading of the boat while running under sail and attempting to drain should encounter the same vulnerabilities and no owner should be excused from due diligence.

Respectfully .... Ross

[Dangerdog]

watching this thread with interest

good luck guys please post results

[Québec 1]

Splashed le Zephyr yesterday at this marina:
http://www.marinadelachaudiere.com/

This is a ramp with nothing alongside and I managed to splash her with relative ease but I splashed her with rudders up and no ballast. First thing the power thruster reduces the motor and splash noise. Secondly with no rudders or ballast at ultra slow speed the control at the wheel was a bit better because I did not have to give her as much short bursts of speed to keep her straight in the water. At higher speeds in 3.5 knot currents she handled a bit better than before. So in these conditions there is not much difference...except that I had the feeling that she was generally easier to control than before (for what that's worth and the placebo effect of anything worth over 90$ ).
Once ballast in and rudders down and at marina no wake speeds she was easier to control than with no thruster ... meaning there was less correcting the wheel when motoring up to the mooring ball.

I'll keep you posted on her further trials.
Q1