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Old 09-09-2007, 21:03   #1
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reversing

hello,

My father and I just bought our first boat. its a 36 center cockpit. When we back out of our slip we need to point the stern to the right. in reverse the stern pulls to the left which is normal. so what I do is i give it some throttle then pop it back to neutral. as I start to move back I move the rudder over and usually all is perfect. but sometimes for reason the boat doesn't want to move to the right. it has happened about 3-4 times so far. I can't figure out what it is. I think it is the wind. but ow do i overcome it. in the marina we get about 1.5 - 2 knot winds. i don't see anyone else having this problem. it has happened in both low and high tides. any ideas or suggestions?
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Old 09-09-2007, 22:26   #2
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Can you give more detail on underwater features. As in, what is the keel and rudder. What Hp have you got, what type of prop. As much detail as possible will help. Otherwise we can only answer, cause it's not a red boat :-)
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Old 10-09-2007, 02:13   #3
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green ones go the other way... : )
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Old 10-09-2007, 02:44   #4
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Boats are primarily affected by tide and wind. The configuration of the boat, both underwater and above water will determine how much the boat is affected by either element.

To overcome the effects (assuming sails all stowed) you have rudder and propulsion.

The combinations of wind, tide, rudder and propulsion added to the innumerable configurations of boat added to the different slip and marina layouts make troubleshooting your problem difficult to say the least.

I suggest you get a couple of good books to understand these effects and then go out to a secluded area of moorings and practice maneuvering your boat around and up to the mooring buoy, practicing coming from different headings and stopping the boat where you want. Spend some time at very slow speed and zero power at different wind speeds in both forward and reverse. Practice u-turns and turning the boat within it's own length using a combination fo forward and reverse motor. Understand the effect of the prop and when the rudder is effective or not.

Practice is the only way to put any knowledge to work.
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Old 10-09-2007, 03:36   #5
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Some more knowledge of the boat and conditions would be helpful. Is this a full keel, modified or fin with spade. If it is a full keel you may end up using a warp to insure that you get pointed in the right direction. Coming out of my slip I really should back to the right but because of the offset prop that is difficult in all bu the best wind conditions. Generally I back to the left and then turn the boat around in the fairway but not all boats can do that.
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Old 10-09-2007, 05:09   #6
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here is some more info.
bulb fin keel
yanmar 27hp
3-blade brone fixed

our sails are down when leaving the slip. practice wise everytime we head out we spend some time doing what you mentioned. we have no other issues in reverse other then at the slip. Slip wise we tie up on the portside and have another boat on starboard.

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Old 10-09-2007, 07:59   #7
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Just a suggestion, if you're only trying to get the boat pointed in the right direction coming out of the slip, use a spring line to get the stern kicked out and pointing the right way. Run it from the dock forward to the bow along your port dock, put the boat in forward until the stern is kicked out and then start backing.
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Old 10-09-2007, 08:27   #8
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Because it is happening only "some of the time" see if you can be sensitive to the tides (currents) and winds when it happens.

I doubt the boat is changing from week to week.

Also Fishpearit give great advise. There is no shame in using well placed lines to make th eboat do what you want. Quite the opposite, it can make you look quite professional. Any good book on boat handling book will cover the use of lines for various docking and undocking situations.
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Old 10-09-2007, 18:13   #9
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Thanks for replies. I will defiantly get a book on boat handling. and i will try to spring line ideas next time i am at the boat.


on another note. when starting my reverse. if i were to use no spring lines should i keep the rudder straight, then once i start moving back cut it. or is it better to keep it turned slightly before i throw her into reverse??
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Old 11-09-2007, 00:51   #10
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Quote:
Originally Posted by turkish6 View Post
if i were to use no spring lines should i keep the rudder straight, then once i start moving back cut it. or is it better to keep it turned slightly before i throw her into reverse??
It depends.

The rudder is completely inneffective with no relative water flow over it.

If you were in a river flowing 10 knots and were floating with the flow (10 knots over ther earth) the rudder wouldn't do a thing. If you were facing up stream stopped (0 knots over the earth) the rudder would have 10 knots over it and would be very effective but you would be standing still relative to trees on the bank.

If you can understand that then try this.

Assume a conventional single screw boat with the prop mounted ahead of the rudder.

If the boat is 0 knots relative to current and you put it in forward and add throttle you will almost immediately get rudder effectivity due to water being forced across the rudder.

In reverse the same boat has zero steerage at that time becuase water is being forced forward. You have to wait for the boat to start moving to get rudder effectivity. In the meantime the boat is affected by current, wind and prop walk.

In your case I can't help but guess that your docks are not "protected" by a breakwater and that they are exposed to a tidal current. I guess that when you have reversing trouble it is because the tidal current is flowing from bow to stern. Let's guess that this current is 1 knot and you need 2 knots relative flow for good steerage. This means that your boat speed (speed over earth) would need to be about 3 kts.

When the tide is flowing the other way (stern to bow) you "already" have a water flow over the rudder (relative speed) of 1 kt and it becomes even more effective as soon as the boat starts moving over the earth relative to the dock. Your relative speed is 2kts and your speed over the earth is about 1kt.

2kts difference around a dock is very noticeable. At our dock we sometimes get almost 2 kts tidal flow.

If all this is true in your case you have a problem - You reeally don't want a heavy boat going 3 kts in reverse (relative to earth, docks and in close proximitely to other boats.)

1/ Check your tide tables or throw a leaf or something in the water to check tidal currents and see if my wild guess has any merit whatsoever. It is a total guess cuz we don't have enough info yet to understand what's happening.

If all the above were true here is how an experienced skipper might do it.

1/ Drop the lines.
2/ Engage reverse idle and let the boat move with the current - rudder neutral or right -
3/ Put the boat engine in neutral - rudder to right -
4/ As the bow clears the pylon engine to forward idle.
5/ Rudder hard left - one medium burst of forward throttle until nose starts to swing left - note do not stop boat - boat still travels in reverse
6/ Rudder hard right engine in reverse idle.

If bow stops swinging left repeat 5 - 6. The key is the power burst in forward "blows" water across the rudder and starts the nose swinging the way you want while keeping a very slow boat speed.

Now add a wind from the port side and none of the above may work. if the wind is strong it just may not allow the nose of the boat to swing left.

Like I said. I depends.

You can practice this technique away from the dock and you should be able to do a 360 almost within the boats own length. Do it within one length of a moring and see how you do. Note how the wind affects the boat as you do these 360s. If you can do a 360 in wind + tide and finish with the boat in the same place you started you are a dockmaster!
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Old 11-09-2007, 01:02   #11
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Dan has given great advice.
One thing I say to newbies in my Marina, go out and practice around the mooring bouy in a secluded bay. No one to worry about seeing you mess up and you can spend some time at your liesure practicing getting to know the boat. Try all the things you ask and see what happens. Every boat is different and will rspond differently and even to the touch of the helmsman. How much rudder you apply and how and when and how you apply the engine and when and so on is all different. You need to know what the boat will do and how it will respond.
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Old 11-09-2007, 10:22   #12
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When we got our previous boat (a heavy full keel 35' cruiser) I set up a "slip" in about 15' of water with a couple of concrete blocks, some fenders with extra line to mark the 4 corners of the "slip". We practiced to our heart's content without any dings to the boat or other people's property. If we missed, we just put the boat in neutral to avoid snagging the vertical anchor lines. My wife loved it.

Steve B.
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Old 25-09-2007, 11:40   #13
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Quote:
Originally Posted by turkish6 View Post
Thanks for replies. I will defiantly get a book on boat handling. and i will try to spring line ideas next time i am at the boat.


on another note. when starting my reverse. if i were to use no spring lines should i keep the rudder straight, then once i start moving back cut it. or is it better to keep it turned slightly before i throw her into reverse??
Yes a spring line. Tie one end off the boats starboard(the direction you want to the stern to go) run it AROUND a stationary object off the starboard side and BACK to the boat with a single wrap on the stern cleat or winch or just hold it. As you back down let the line slip and when you want to start the stern moving over, simply stop it slipping. when you're out let go and pull it back in. I usually just hold the line in my hand and let it run or hold off as needed. If you have to provide lots of pull to effect the stern movement simply take a turn or two around a starboard sheet winch. This method works great for single handing as the line is in your lap and you get it all back. Obviously you don't want to drop the line or let it get under your stern as you back. IF it does for any reason take her out of gear NOW and retrieve.
Use the rudder to help or at least not fight the turn, so in your case put her to starboard.
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