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Old 30-10-2019, 03:54   #1
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383 morgan,prop walk astern

Does anyone have any suggestions on going to starboard astern,she will only go port astern?
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Old 30-10-2019, 04:32   #2
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Re: 383 morgan,prop walk astern

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Does anyone have any suggestions on going to starboard astern,she will only go port astern?
Some boats just wonít go. You learn to deal with it and plan ahead. I know it might not seem like it sometimes, but strong prop walk is better than not being able to steer at all in revelse, which some boats wonít.

Your best bet to get some starboard control, is short bursts of reverse, enough to get some speed with but more coasting than running. It can work, but it will never do well to starboard. If the prop isnít turning, you get no walk, and the rudder has a chance to work.

Some boats will also respond to port rudder while backing with short hard bursts of forward to swing the boat.

No one answer works for all boats, and for some boats nothing really helps.
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Old 30-10-2019, 04:32   #3
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Re: 383 morgan,prop walk astern

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... If the prop isn’t turning, you get no walk, and the rudder has a chance to work ...
Indeed.

In reverse, and at slower speeds, your rudder is much less effective, so prop walk (asymmetric blade thrust) is more obvious and more difficult to control.
To steer a single-screw vessel in reverse, it is usually best to get her moving gradually.
When possible, start with the stern at an angle (20 to 40 degrees) to the desired direction (cocked to starboard if the prop is right-handed, to port if left-handed).
The angle will quickly be corrected, by prop walk, as you begin backing down.
By the time the boat straightens out, she is making sternway, and the rudder is biting. Steer against the prop walk to compensate for it.
Then throttle down to idle reverse, or shift to neutral to decrease or eliminate the walking, and steer with the rudder as the boat eases back into the slip.
If necessary, you can readjust the angle, midway, with a quick burst of power in forward (with the rudder cocked) or reverse.
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Old 30-10-2019, 06:07   #4
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Re: 383 morgan,prop walk astern

It's worth pointing out that prop walk can help you to spin the boat, clockwise, in little more than its own length. Sometimes it's easier to just spin the boat around, depending on the situation and goal.
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Old 30-10-2019, 08:07   #5
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Re: 383 morgan,prop walk astern

Prop walk is a product of physics, not the make or model of the boat. My boat walks to stbd in reverse. If I want to back stern into a slip, I opt for a finger pier to stbd. Likewise, if I need to turn around, I turn to port, so as I 'bump-and-fill', I turn rudder hard to Port, an back to Stbd and bump fwd to port and rotate the boat counterclockwise in just about it's own length.

Prop walk actually works in fwd too. If I attempt to make a 360 degree circle, the diameter of my turn is greater when circling to Stbd than it is to port.
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Old 30-10-2019, 09:03   #6
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Re: 383 morgan,prop walk astern

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Prop walk is a product of physics, not the make or model of the boat...
Prop’ Walk generally occurs when a prop and its shaft are not perfectly parallel to the water’s surface. When the shaft is angled downward, as most are, the cylindrical distance traveled by the propeller blades on their upstroke is greater than on their downstroke. The upstroke pushes more water, generating more thrust on that side.
This, coupled with lateral deflection off the hull, pushes the boat’s stern sideways, pivoting the vessel around a point located about one-third of the boat’s length aft from the bow.
It is less pronounced when a prop is in shallow water (i.e., on a boat with shoal draft), as this reduces upward water flow from beneath the vessel.
The amount of clearance between the propeller and hull has an impact, as does the hull’s shape.
Increased wheel diameter or blade pitch increases prop walk.
Two-blade props walk less than 3-blade props; folding and feathering props walk less still.
An offset shaft may alter the effect, and when a shaft is parallel to the water’s surface, as in a saildrive, its prop doesn’t walk very much at all.
All of these physical phenomenon are affected by the boat’s configuration - different for each make & model (design).
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Old 30-10-2019, 09:19   #7
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383 morgan,prop walk astern

Gord, I believe your talking about P factor which of course requires induced flow, https://en.m.wikipedia.org/wiki/P-factor
However outboards and sail drives have prop walk too with zero thrust angle, my boats prop angle is nearly zero, and yet it had epic prop walk with a fixed prop, and nearly zero prop walk with the Autoprop.
I believe prop walk is greatly affected by pitch, a prop with a lot of pitch, has a lot of prop walk.
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Old 17-12-2019, 07:47   #8
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Re: 383 morgan,prop walk astern

My best advice to you is to review the above comments and learn how to work with it and not try to fight it. I own and operate a Morgan 382 and am a professional boating coach and consultant. I operate hundreds of power and sail boats, single and twin, inboard and outboard, diesel and gas and with different props and running gear and I like the strong propwalk on my boat because it is consistent and predictable. Nothing beats a training session with a pro (I have to put that in of course) Other than that, try a max prop--but they cost many boat units. I have some blogs posts about backing a boat into a slip. Feel free to contact me paul@foerfront.com .
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Old 17-12-2019, 08:34   #9
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Re: 383 morgan,prop walk astern

My father-in-law, a Panama Canal pilot, said that the only ship he ever managed to steer in reverse was a three propeller detroyer. That said, take her out into some calm water a practice hovering. It is a wonderful way to get a feel for your boat. Bring her to a stop. Set the throttle at idle. Click into reverse for a few seconds. Her stern turns. Give a gentle burst in forward, just enough to stop her motion and creep forward. You are turning. Another gentle burst in reverse. Keep your eyeballs on surrounding landmarks so you can gauge turn and shift. Soon you are hovering in place, a useful skill in crowded marinas and while waiting for locks to open.
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