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Old 05-18-2015, 11:04 PM   #21
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Thanks for all the good info, I talked to the lewmar tech and he said my 150 breaker was toooo small to replace with 250. So I did thruster has not failed, I am staying to the 15 to 20 sec burst which seems good!! Hanks again to all
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Old 05-18-2015, 11:43 PM   #22
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Great to hear you're back in business. I think I may have solved my bow thruster problem for now - at the expense of having the low power setting - which I don't really use anyway. With hydraulic thrusters you can run them all day long - no overheating.

Still practice those maneuvers though. Your engine is way more powerful than your thruster and will still help you get the bow into the wind when the thruster won't.

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Old 05-18-2015, 11:54 PM   #23
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Thanks for all the good info, I talked to the lewmar tech and he said my 150 breaker was toooo small to replace with 250. So I did thruster has not failed, I am staying to the 15 to 20 sec burst which seems good!! Hanks again to all
With all due respect, 15-20 seconds on the thruster is relying on it too much....strictly my opinion. You should get to the point where the thruster is only needed for very short bursts. If you need it for more than that, you need to more practice.
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Old 05-19-2015, 12:10 AM   #24
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With all due respect, 15-20 seconds on the thruster is relying on it too much....strictly my opinion. You should get to the point where the thruster is only needed for very short bursts. If you need it for more than that, you need to more practice.
Or it could be undersized. 15-20 would spin my boat 360.
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Old 05-19-2015, 12:21 AM   #25
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Or it could be undersized. 15-20 would spin my boat 360.
Same here
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Old 05-19-2015, 12:37 AM   #26
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Or it could be undersized. 15-20 would spin my boat 360.
Probably about 120 for mine...
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Old 05-19-2015, 12:42 PM   #27
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As others have mentioned, most single screw boats will not back in a straight line - at least not until you can get enough way for the rudder to bite.
Britannia, I'm not trying to pick on you! But the way you put that could be misleading.

Actually you can back a single-screw boat in a straight line as slow as you like, just not by only using reverse gear, and it's another maneuver well worth practicing.
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Old 05-19-2015, 12:48 PM   #28
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I would actually call any use of throttle and gears with even small rudder changes .... "maneuvering" in reverse.


Backing to me is putting an engine in reverse and only using rudder.


Either way...planning on going dead center right down the middle of a fairway in rearward motion is going to be challenging no matter.


Sure really good guys make it look easy...but it's not because the average boat is making it so.
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Old 05-19-2015, 01:04 PM   #29
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Britannia, I'm not trying to pick on you! But the way you put that could be misleading.

Actually you can back a single-screw boat in a straight line as slow as you like, just not by only using reverse gear, and it's another maneuver well worth practicing.
No problem - not feeling picked on. I try to use fewer words since I'm often accused of being too wordy!

Out of curiosity - what's your technique for backing up in straight line at speeds lower than that where the rudder starts to become effective? The only way I know is a short burst in reverse and then to neutral to let the boat's momentum take it in a straight line.

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Old 05-19-2015, 01:08 PM   #30
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...
Backing to me is putting an engine in reverse and only using rudder.
...
Yes - that's what I meant.
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Old 05-19-2015, 01:39 PM   #31
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My little Albin was great for rudder controlled backing.

Hold the helm w both hands though.
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Old 05-19-2015, 02:46 PM   #32
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What's your technique for backing up in straight line at speeds lower than that where the rudder starts to become effective?
The basic idea is to use bursts of forward power over the rudder, enough to counteract the effects of prop walk in reverse gear, but not so much that you kill all sternway.

With a left hand screw like your boat, prop walk in reverse will push the stern to starboard. So to counteract that, put the helm hard to starboard and give a little burst of forward power; propwash over the rudder is very effective and will push the stern to port.

Step-by-step would be something like this:
1. Throttle idle, gear neutral
2. Helm hard to starboard
3. Gear reverse, a little throttle for sternway until you see some starboard propwalk
4. Throttle idle, gear forward, burst of throttle to counteract propwalk as much as needed
5. Throttle idle, gear neutral, and go to 3.
Of course if in doing this you are applying enough reverse power to continue to increase astern speed, rudder effectiveness in reverse will increase, and with the helm to starboard, its effect is adding to propwalk! So at some point you will want to bring the helm past center a bit to port and steer normally. That point is different for every boat, and this transition is also something that's worth practicing.
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Old 05-19-2015, 02:59 PM   #33
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Either way...planning on going dead center right down the middle of a fairway in rearward motion is going to be challenging no matter.
I learned to back a single-engine boat in England with a 60' narrowboat. Sixty feet long, six feet ten inches wide, twenty tons, dead flat bottom, tiller steered, single Lister diesel.

What I learned about in a huge hurry is inertia and how to use it. Inertia, of course, is not just the tendency of an object to keep going but it's also the resistance of an object to get going.

Once I learned to judge and use inertia, as well as the effect of the rudder and the propwash against it, I was soon able to back that boat down a 100 yard channel between two rows of moored boats with about a foot of clearance on either side and not touch any of them. (It's a different story in a crosswind)

This is not an "aren't I great" thing---- every experienced narrowboat driver can do this. But the lesson I learned about the value of inertia and how to use it to my advantage has paid off big time in the single, twin, and tripple engine cruising boats we have run or are running today.

Boaters who are good at maneuvering are using inertia to their advantage even if they don't realize it. But if you actually learn what this force is doing, both for and against you, and then make use of it consciously, it makes a huge difference in my opinion to one's boat handling skills, regardless of the type of boat or how many props it might have.

Backing a twin engine cruiser with counter-rotating props in a straight line is dead easy, of course. In fact, we often spin our twin engine PNW boat around and back into a tight spot rather than go in forward because with differential thrust and power it's no different than driving a car forward and directional control is very accurate.
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Old 05-21-2015, 12:55 PM   #34
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The basic idea is to use bursts of forward power over the rudder, enough to counteract the effects of prop walk in reverse gear, but not so much that you kill all sternway.

With a left hand screw like your boat, prop walk in reverse will push the stern to starboard. So to counteract that, put the helm hard to starboard and give a little burst of forward power; propwash over the rudder is very effective and will push the stern to port.

Step-by-step would be something like this:
1. Throttle idle, gear neutral
2. Helm hard to starboard
3. Gear reverse, a little throttle for sternway until you see some starboard propwalk
4. Throttle idle, gear forward, burst of throttle to counteract propwalk as much as needed
5. Throttle idle, gear neutral, and go to 3.
Of course if in doing this you are applying enough reverse power to continue to increase astern speed, rudder effectiveness in reverse will increase, and with the helm to starboard, its effect is adding to propwalk! So at some point you will want to bring the helm past center a bit to port and steer normally. That point is different for every boat, and this transition is also something that's worth practicing.
Ok - we're saying the same thing. I was talking about backing down with engine, not maneuvering as you describe - which works fine as you say. I'm not sure anyone was misled by my statement though.

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Old 05-21-2015, 01:25 PM   #35
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Backing to me is putting an engine in reverse and only using rudder.
Boats tend to pivot with rudder, not steer one end while the other end stays put. So simply backing with reverse power only in a single engine boat and trying to hold a straight line with the rudder will very often not work, particularly at slower speeds and especially if one needs to back a significant distance.

The process described by Britannia is the way to maintain a dead straight line going backwards at a consistent speed. While he did not use this term in his description, the process he describes works because it uses inertia to maintain the boat's track and orientation with the brief shots of forward.

Even the skippers in the fabled Chesapeake Bay commercial boat docking contests use this technique. If you listen to their motors while watching the video you'll hear the the quick forward thrust "correction"--- usually just one-- as they back in at a high rate of speed. The boat itself does not slow down, yaw, or vary from its track. But that brief shot of forward stops the stern's swing to one side while the bow swings to the other even before it begins. It's a great example of judgement and intimately knowing the boat's response to propwalk, rudder and inertia.
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Old 05-21-2015, 02:27 PM   #36
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Thanks for all the good info, I talked to the lewmar tech and he said my 150 breaker was toooo small to replace with 250. So I did thruster has not failed, I am staying to the 15 to 20 sec burst which seems good!! Hanks again to all
Gosh, I'd really love to have a thruster, but I make friends with the wind and current and ease in gently. Sometimes I pivot off of the out-piling. Good crew helps!

Seriously, I check where that wind is gonna blow me and set the boat up accordingly and have no shame in a do-over. I have a sundeck - and have very little visibility through the opaque roof. So I learn the feel of the boat and prop pull and have practiced lots of times.
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Old 05-21-2015, 05:25 PM   #37
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What is method to stick Regis. # on rubber inflatable dingy??
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Old 05-21-2015, 06:11 PM   #38
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What is method to stick Regis. # on rubber inflatable dingy??
Well, first you're going to have to learn to back your single engined dinghy in a straight line...
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Old 05-21-2015, 09:16 PM   #39
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I'm not sure anyone was misled by my statement though.
Very good. Just didn't want folks to get stuck with the idea that it's impossible to back a single-screw trawler in a straight line, especially at slow speeds.

Here's a link to another explanation about how to do it. Maybe it will help someone: http://www.his.com/~vann/KrgStuff/360turns.htm
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Old 05-21-2015, 10:23 PM   #40
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Actually, QB, I was referring to your post #32 in my comments in my post #35. I mistakenly attributed your comments to Britannia because I was reading your backing description off his post.

Sorry about that. I don't like attributing things to the wrong source. It was your description of the backing process which I felt was very good.
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