Prop Walk - 30 degrees to port

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Adria
Adria's picture
Prop Walk - 30 degrees to port

Or, “sporty boat handling”.

The Maine lobstermen run their boats up to a working pier at speed (probably significantly more than 5 knots) and at an angle of approach of perhaps 30 degrees, then turn hard to port, heavy throttle astern, and slide the stern into the pier within a boat’s length.  (Yes, it leaves the moored boats bobbing in the harbor.)

My own version of that approach was lots of fun and very useful on many occasions, and enabled me to tuck into a space not much more than my boat’s length.  It requires an aggressive use of throttle to control and direct momentum, and there is a fine line between “aggressive” and “excessive”.  So one needs to develop a feel for the maneuver before putting it to the test.

Several more extreme uses of aggressive reverse throttle include (i) backing in a straight line, and (ii) throwing the stern to port in a hard turn to starboard. 

My preferred aggressive backing technique involves short, high acceleration with rudder hard over, followed immediately by returning throttle to idle or even neutral (to eliminate prop walk) and then steering with the rudder while coasting back.

I also found, but did not master, an aggressive level of reverse where the bite of the rudder would neutralize the prop walk effect.  Best attempted only with lots of room and no traffic!

In approaching a hard turn to port while slowing in reverse, it is easy to use prop walk to pull the stern around to starboard and sharpen the rate of turn while slowing the boat.

But I also discovered that in doing the same thing turning hard to starboard it was possible to skid the stern to port - at just the right reverse throttle it seemed to “break loose” of the prop walk (possibly due to cavitation).  My best use of this was purely accidental - I never actually bothered to learn how to do it at will.

I have been told that my approaches sometimes appear “too fast” but i have never clipped another boat or banged a pier.  I have suffered scrapes from unrecognized projecting objects on piers though, and scrapes from other boats tied too loosely astern of me in close quarters.

As venturesome cruisers we did not have a home port and, though we swung at anchor whenever possible, we did encounter endlessly varied docking and mooring conditions.

Richard M
[Cross-posted from Yahoo #17483]

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Weebles
Weebles's picture

I used to use Weebles as a teaching platform for a 2-day boat handling class in San Francisco. Also used to teach at TrawlerFest, so I have noodled on topic of docking trawlers for a while beyond just doing it a bunch. Here's my routine - would be interested in thinking from others:

1. The 30-degree rotation from prop-walk sounds about right, but it is not even. Most of the rotation occurs as the boat comes to a stop. I've seen commercial boats do as Richard M observes and blast into a dock "Captain Ron" style. They do it because they can, not because they have to. 2-1/2 to 3-kts is plenty of speed to induce the rotation. Interestingly, bow thruster effectiveness also decreases with speed - faster you are moving, the less effective the thruster becomes.

2. There is Prop Walk in forward as well as reverse, but it is overwhelmed by rudder wash - a whisper in a rock concert.

3. Make all reasonable efforts to dock in a direction where Prop Walk helps - meaning it will bring your stern to the desired direction (exception: sometimes you have to chose between prop walk and mother nature - see #6 below).

4. Most people (myself included) undershoot their landing versus over-shooting it. This means two things: turning too early and/or expecting too much drift - unlike shallow planing hulls, Willards do not drift or slide much. Imagine coming up to a long floating fuel dock and needing to land in a space between two boats. Pick a spot on the dock that is 5-8 feet behind where you want the bow to end up and aim right for it at 30-ish degrees, at 2-kts or so (slow walking speed). When you're 10-feet or so off the dock, throw the helm hard to port and go to reverse. Modulate reverse so the bow comes very close to the dock, perhaps with a short burst in forward to kick the stern towards the dock. If you start the sequence to early, you will land too far off the dock. Start it too far back and you risk clipping the boat astern - most boats have great forward visibility, not always great at the stern. If you know there is enough room for your boat between the two docked vessels, keep the bow close to the forward one, and the ass-end will take care of itself.

5. Docking to the 'wrong' side is possible by giving bursts of forward against a hard-over rudder as Richard M describes, but a lot can go wrong if there are any adverse currents or winds. Your speed will need to decrease to lower potential for prop-walk when you hit reverse. And, using the long-dock example, your angle of approach will need to reduce.

6. There are only a few tools in the toolbox: prop walk is certainly one. Rudder-wash is another. Bow thruster is still another. But sometimes mother nature lends a hand with wind or current in a favorable direction. Sometimes you have to make a choice - imagine the long-dock example, except its town guest dock along a river and runs parallel to the current. You have a choice of (a) landing to starboard, the preferred side for almost all Willards but that means you have to approach going down-current. Or (b) approach up-current, but it means landing to port and prop-walk becomes a foe. Personally, I'd take (a) because I can try to 'sail' her on the current side-ways into the dock. At least that would be my plan.

That's the theory - doesn't always work out that way. I was amazed at how rusty my boat handling skills had become during my 10+ year haiatus. Last month when I was in Ensenada, I needed to move Weebles to a different marina. Exiting my slip meant backing-out and making a left-hand rotation to exit the fairway - easy-peasy as Weebles backs to starboard anyway. Granted the fairway was narrow so I didn't have much room to back-down, and the slips were so I had to make a 135-degree rotation to port instead of 90-degrees, but the winds were calm so should be a no-brainer. Except I totally mis-read the current (read: I didn't even look - turns out it was coming astern, meaning pushing me back into my slip) and found myself horribly jammed-up, unable to get my bow around to port and being pushed towards the other docked boats. Try as I may - and I was trying everything I could think of, I just couldn't get the boat through (in hindsight, I should have backed-out of the fairway). Thankfully, during my brief stay at Baja Naval I had made a friend in Victor, a workman on the dock, who rescued me by stationing himself on the stern of a sailboat and pushing my bow through. It was a memorable experience, meaning I cannot erase from my memory no matter how hard I try. To my defense, I've docked a lot of boats over the years and I have a pretty high batting average, but not 100% - I've never had an insurance claim, but been too close for comfort and my ego has taken a beating a couple times.

So, after 20-years of ownership, I will have a bow thruster installed. And I am seriously interested in the articulated rudder. Sign me up for all the docking tools I can afford! Cheaper than fiberglass repair, and means I can be comfortable using the boat more

Peter
W36 Sedan
Ensenada

Lady Anne
Lady Anne's picture

Richard-

This is absolutely the best description that I have ever read describing maneuvering a single screw vessel. Everything that you describe are techniques that I’ve learned from years of attending the Willard School of of Hard Docks! I’m going to file away your write up for future reference and information to pass on to other single screw operators.

Thank you very much,
Rob Hays
“Lady Anne” W40PH & “Lady Anne II” Kady-Krogen 42
La Conner, WA.

Adria
Adria's picture

Rob,

That’s a wonderful compliment, especially coming from you, Rob.  Many thanks,

Richard M

Weebles
Weebles's picture

One of the learning experiences in moving to Florida is the difference in docks: Along the East Coast, docks are almost universally fixed concrete docks versus floating docks along the Pacific Coast - East Coast worries about storms/hurricanes, Pacific Coast deals with tides of 6-feet or more. The fingers on fixed concrete docks are rarely much longer than 2/3rds the boat length, so a 40-foot slip may only have 20'-25' of walkway so boats almost universally back into their slips. Setting lines to piles versus cleats is a bit different too.

Guest (not verified)

Maybe in Florida, but in South Carolina and Georgia we have 6'-9' tides and essentially all recreational docks are floating.  Much of the time, the current is strong enough to approach against it and "hover" in place parallel to the slip.  Then with minor adjustments to throttle and rudder I can move "sideways" into the slip with little or no reverse.  This is my preferred approach for a port side tie.  If the current is not screaming, I will approach with it for starboard tie and reverse to walk the stern over.  It's  rare that we have no current.  Springlines can be most helpful too!

Perry Dukes
Dubhe (Vega Nomad)
Beaufort, SC

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