Using Prop Walk To Turn

[Don Guillette]

Mates: I was having breakfast this morning in Long Beach and watched a sailor trying to dock his Catalina 30 in a narrow slip way. He missed his slip and then a Chinese fire drill broke out as he bounced off boats trying to turn the boat around.His problem of turning his boat in a narrow area could have been easily avoided if he had used "prop walk" to his advantage. The technique is called "backing and filling" and enables you to almost spin the boat within its own length. Here is how you do it. Assume your boat kicks or walks to port when you put it in reverse. If it kicks to starboard, no big deal. Just reverse the process I'm about to outline.Step 1: Start the turn in forward and turn the wheel hard over to starboard and gain a little headway. DO NOT MOVE THE WHEEL FROM THIS POINT THROUGH THE REST OF THE TURN!! Step 2: Keep the wheel hard over to starboard and now shift to reverse. Your stern will turn to port. At this point you should be about 40% to 50% through the turn.Step 3: When you get 50% into the turn, shift to forward still keeping the wheel hard over to starboard. Gain a little headway - little is the key word.Step 4: Once you gain a little headway, shift to reverse, still keeping the wheel hard over to starboard. The stern will again start to kick over to port.Step 5: At this point, you should have completed your turn and be headed in the opposite direction so just shift to forward and be on your way.A couple of points - water must be flowing past the rudder for it to have any effect and this happens much faster in reverse than forward. Additionally, you MUST resist the temptation to touch the wheel during this process.One last point. Obviously, the place to practice this is in the middle of your turning basin. After you see how easy this process is, narrow slip ways will never again be a problem to you.While I was finishing eating breakfast, I wrote this method on a napkin and then walked down the dock to the C30. On board the boat were a husband and wife. Both were frazzeled. At first, the husband didn't want to hear anything but the wife said "this guy is trying to help you so don't be an idiot". Woman are just so much more open to things than men. After that we had a great conversation about boats and sailing etc. Turned out they were new to sail boats and still trying to figure out the boat.

 

[Rich]

How true

DonHow true it is what you said in your post..about backing and filling and the other thing about some folks being more open to things than others.Took me (a guy) about two seasons to learn the back/fill trick. What a joy it is to use!!Also it's taken a lifetime to learn the other thing.Hope Long Beach isn't too bad weatherwise right now.I was in the yards in San Pedro in Feb '83 during a massive series of storms which destroyed Santa Monica pier and caused our 14,000 gwt ship in an old, wooden, floating drydock to take small, but sensible rolls. scary.

 

[Paul Akers]

It's amazing...

...how many people don't understand propwalk. It's one of the most useful tools in a skipper's maneuvering arsenal, once he learns to master it.I'm not a professional, but self-taught myself just by playing around with it. The same can be said for steering a boat. Many sailors will turn a boat by trying to point the bow. A sailboat actually steers by moving the stern about and aligning the bow.

 

[Tim McCarty]

Probably not related, but maybe....

Don, two questions...1. do you get more or less prop walk with a 3 blade prop vs. two blade?2. do you get prop walk with a sail drive system?I will be taking ownership of a new Cat 310 (with a 3-blade prop and 27 horsepower engine). I've managed to "somewhat" master prop walk and turning etc, however this was always on a two blade prop. Also, my brother in law has a C&C 99 with a sail drive system, and I just wondered if prop walk comes into play. Thanks in advance...

 

[Don12364]

Water Speed?

Don,You say water flows much faster across the rudder in reverse than in forward. My understanding is just the opposite as the prop wash will give a faster flow when in ahead.Otherwise I agree everything you say and do it regularly.Kind regards and thanks for a great session.Don.

 

[Don Guillette]

Donalex: I don't know myself. I got that tidbit from the Matec prop people in Long Beach, Ca. They are the people that make a folding prop.

 

[Ed A]

more with 3

you get a good bit more walk with a three blade, some people view that as bad, I think its great.Yes you get walk with a sail drive. just about any prop does walk some. a full keep or the like my be effected less and fin keel more as the boat can pivot on the keel.

 

[abe]

Why the wheel to starboard better than neutral..

I can understand why going forward keep wheel to starboard. But why do you keep it to starboard when in reverse? Better flow?abe

 

[John Nantz]

Better Trick: Try Walking Boat Sideways

Turning a sailboat in it's own boat length is certainly a fun thing to do in front of a bunch of powerboaters but what's an even better trick is walking your sailboat sideways, like up to the dock!This can be done also using prop walk. Last September I went into Queen City Yacht Club on Vancouver Island and was greeted by a number of guys giving directions and finally, without any consensus, decided I would do it my way and selected the one small piece of dock available and sallied up to it sideways from about 15 or 20 feet out.When I first started one of the guys hollered "Turn on your bow thruster!" and to that I naturally replied "I don't need no stinkin' bow thruster" and just walked the boat sideways to the dock. Talk about some amazed guys!Another time (I REALLY enjoyed this one) was when I went to one of our yacht club rendezvous' and encountered a similar situation with everybody standing around barking different directions and we were away from the dock quite a distance and I did the same thing - just walked the boat sideways. Guess there are choices in life: in a similar situation, one can either "drive" the boat out while getting some weigh-on and then return with rudder steerage, or, use prop walk and just walk the boat sideways. The latter is definitely a lot more fun when the conditions are right and there are people standing around.I suppose still another alternative is to throw everybody your dock lines and let them pull you in but that's not near so kewl.Bottom line is prop walk can be a really good thing.

 

[tom]

you did not tell how to do it!

You now need to tell us how to walk the boat sideways!

 

[Malcolm Young]

Why prop walk occurrs and why rudder to starboard

You don't have to know why prop walk occurrs to use it. Don's description of how to use it was right on. That said it is still interesting to know why this occurrs. I came across this reference of why prop walk occurrs. See link below.The information in the link matches what I have heard and experienced before but explains it better complete with diagrams. Prop walk depends on the angle of the prop to the surface of the water. You have very little prop walk with a sail drive as there is no angle. I have chartered a number of boats over the years and owned a 32' boat and have a C36 now. All of the boats I have owned and chartered had some up to a lot of prop walk... with one exception and that was a Bavaria 37 with a sail drive which had virtually none. The reason was that the prop discharged parallel to the surface of the water and the prop was a long distance from the rudder. With no prop walk - I found it challenging to do what I wanted to do. Although I will agree that it was somewhat easier with no prop walk to back into slips to the starboard (which we had to do in Croatia where we had the charter).This brings me to Abe's question - when turning to starboard why do you keep the rudder to starboard in forward and reverse? You need to understand first that the boat does not move much in the forward or reverse direction during the whole manoever. You are basically rotating. You keep the rudder to starboard throughout as the main force in forward is caused by the discharge current from the prop impacting the angled rudder thus forcing the stern to port. In reverse it is the prop walk that takes the stern to port, the rudder does little. This happens as there is little forward or reverse motion through the water so the rudder has little effect. In reverse the discharge current is going forward and does not impact the rudder. The suction current from aft of the prop is diffuse (not directed in a line) and therefore has no signficant impact on steering.Turning to port is altogether another matter (still possible as discharge current and prop walk in forward helps but prop walk in reverse fights you). If turning to port, I find that short bursts of forward power (so the discharge current impacts the rudder) interspersed by neutral (to keep speed down) is about as good as you can get. In any case you need much more room to turn.

 

[Wayne Elphinstone]

Berthing

Hi all I liked this discussion and I do struggle with my C380. Where I berth in Melbourne there is always Southerly winds which come onto my port side, this obviously pushes my boat onto the the starboard side of the mooring. I always motor in slowly and then reverse, I have to grab the stern ropes while doing this and cleat them, this stops the boat from going to far forward. By the time i get up to the Bow to grab the ropes, the bow has been blow onto the mooring. How can I stop this from happening?

 

[Malcolm Young]

Wayne - Some suggestions to keep bow up against the wind

I am making some assumptions in this answer which may not be correct. I will state them up front. The first may be a difference of terms used in North America vs Australia. By mooring I think you mean what I would call a slip. I assume you have a finger dock or a tie point on your port side at the stern. (Generally in my experience mooring is used to describe a mooring buoy which is firmly anchored to the bottom and to which you tie your bow).I hope that you have a midship cleat as that will make things a lot easier.In the situation that you describe with a dock on your port side I would do the following. Take a spring line from the port midship cleat and tie it back to the dock cleat that you normally tie your stern line to. As you come in to the slip, reverse the boat to slow but not completely stop the boat. As the boat comes to a stop against the spring line steer to port and shift to forward - leave the power on at idle. The boat will stop as the spring line tightens and the bow will be pushed upwind to port as the rudder pushes the stern slightly to starboard as a result of the discharge current over the rudder. The stern will not go far to starboard as the spring line will pull it in.With slow forward power against the spring line the boat will stay against the dock as you tie the bow line and stern line on. You may have to use more power if it is windy.If you watch ferries or the like tie up you will see them always using this method to keep the ferry tight against the dock.We were down in Melborne 2 years ago - camped across Australia for 4 months. Sailed (and snorkeled) in the Whitsunday Islands - nice.

 

[John Nantz]

Wayne - another trick for you....

I'm also going to make some assumptions: That the "mooring" is a boat slip or floating dock, that you dock the boat bow-in and this wind sets you off from the dock.The midship cleat suggestion would be the first one I'd go with because it's more "yachty", but here is another. Nothing like a bag of tricks, eh?Install something that is thick and soft on the main dock which your bow is pointing to. Say, old fire hose, doubled up carpet, and old car tire stretched out (if your hull is a dark color or in that case paint the tire white), or the like.Now when you come in just kiss the bow on the dock in front where you placed that proector strip and keep forward thrust applied to keep the bow "nailed" there. Then hard over with the rudder to walk the stern over to which ever dock you want to side-tie to.The main thing would be to provide enough protection on the main dock so that at the approach speed you don't either bang up the dock or nick the gel coat on your boat.Once the boat has kissed the dock and you nail it there you can apply quite a bit of power without damaging either your boat or the dock. For docks which you are visiting maybe carry some carpet (several layers fastened together) along and tie it off to the two forward cleats? The forward pressure may have to be a bit more to keep the bow nailed, though, because the carpet isn't fastened to the dock. I've never done this but I think it would work.

 

[henkmeuzelaar]

Caution: in a fresh breeze, work WITH the wind!

If your vessel has high bows, chances are you will be unable to "propwalk" or "back-and-fill" your bow through the wind in a fresh breeze. When manoeuvring in tight quarters in a breeze my advise is to first figure out in which direction your bow is going to blow off before trying to manoeuvre AGAINST the wind rather than WITH it.However, in sheltered conditions I fully agree with the procedure outlined by Don and other posters. Flying Dutchman

 

[Wayne Elphinstone]

Thanks John and Malcolm

Thanks Guys, I should not have mentioned Moorings I berth in a pen.I went out on Saturday and did some playing around, did a few prop walks and just experimenting with the prop and the rudder. I found berthing that evening was so easy. I have learnt so much reading how you all handle certain situations. I think your suggestions will work, I will try them next weekend.Thanks