Was Told I Need Bigger Rudders

On my 45 ft Bluewater Coastal Cruiser I was told that I have high speed rudders and that's why it is hard to dock or control at low speed. Is there a way to add on to the rudders to get a larger surface or due I have to buy new rudders.

kartracer said:

On my 45 ft Bluewater Coastal Cruiser I was told that I have high speed rudders and that's why it is hard to dock or control at low speed. Is there a way to add on to the rudders to get a larger surface or due I have to buy new rudders.

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Huh? Twin screw?

I rarely touch the steering wheel when I am docking... I center the rudders and work the throttles...

Who told you that?

And like Mystery said, most vessels with high speed rudders seldom touch the wheel at slow/docking speeds, that's what the twin engines are for.

Depending on what your rudders are made of, you may be able to add to them. You could have new larger rudders fabricated or you could install articulated rudders.

kartracer said:

I was told that I have high speed rudders and that's why it is hard to dock or control at low speed. QUOTE]

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There are some threads about adding on to a rudder to make them more responsive. Although if you have twins using the rudders at slow speeds isn’t that necessary.

One, you really shouldn't need them...

Two, if you decide you do, like someone said in another thread....there is tons of used parts from recent hurricanes available. Just a lot of work to locate a set.

We have what you would call high speed rudders too. I call them my ping pong paddles. And yea, low speed maneuverability is cruddy when you use rudders... and you can a little bit. Still, bigger rudders will cost you a great deal of speed due to drag. I don’t think it would in any way be an easy or cheap job. It might be cheaper to add a thruster if you don’t have one. You would need new tillers and stuffing boxes and I would bet custom fabricated rudders. Moreover, will your steering be able to push the greater mass and against the pressure more water will create? I know this post is more questions than answers, but TBH, you should be able to get used to handling her as time goes by (assuming this boat is new to you).

kartracer said:

On my 45 ft Bluewater Coastal Cruiser I was told that I have high speed rudders and that's why it is hard to dock or control at low speed. Is there a way to add on to the rudders to get a larger surface or due I have to buy new rudders.

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In general, rudders on semi-displacement or planing hull boats are of little use at slow speeds, and are completely useless in reverse. The small size of the rudders is more about the draft of these vessels than about 'high-speed'.



With twin engines, you want to center the rudders and use the sticks.


I have seen some boats 'upgraded' with a (very expensive) articulated rudder, but these are generally single engine boats.


Find an experienced friend (or hire a captain) to show you how to steer and manuver with the sticks...

kartracer said:

On my 45 ft Bluewater Coastal Cruiser I was told that I have high speed rudders and that's why it is hard to dock or control at low speed. Is there a way to add on to the rudders to get a larger surface or due I have to buy new rudders.

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I had run a twin with fairly small rudders for years. It docked wonderfully. IMO, if running at any speed with ONE engine and you can't go straight ahead; the rudders are too small.

I had the rudder enlarged on my single engined previous boat and it made a huge difference to turns, they used the old rudder base and built on it.
But with twins, you have the turning effects the props create, in addition to fwd/aft propulsion. For close quarters work requiring concentration,I simplify by centering the rudders, lowering rpms to near idle, leave the rudders and throttles alone as much as possible, and go in and out of gear as required. Some instruction might speed the learning process and help put together a series of things you probably already know.

Well, I hate to throw a bucket of cold water on those who say you don’t need rudders to dock a twin screw boat but I would disagree. Use of rudders while docking greatly enhances the bag of tricks at hand for variable conditions including high current, breezy days and tight spaces. You will need rudders to walk a boat sideways into a berth. If you don’t know how to do this, have someone show you how, it will certainly enhance your boat handling skills. Although I have a bow thruster, I seldom find use for it as I use my rudders in conjunction with engines to get into tight spots. Oh and btw I consider my rather small rudders to be a detriment and would rather have larger but they work well enough for me to single hand my 53’, 62,000lb boat into most berths.

I have used helm turning 90 degrees to line up and back into the berth but, there is a risk at a busy time of forgetting to straighten the rudders. Though one time I left the helm over it helped angle the boat into the berth. Rules like "not touching the helm" are made to be broken.
Walking the boat sideways using helm has been discussed before but I recall many contributors could not make it work on their boat.

A little throttle burst will overcome lack of rudder size if you need it.

McGillicuddy said:

Well, I hate to throw a bucket of cold water on those who say you don’t need rudders to dock a twin screw boat but I would disagree. Use of rudders while docking greatly enhances the bag of tricks at hand for variable conditions including high current, breezy days and tight spaces. You will need rudders to walk a boat sideways into a berth. If you don’t know how to do this, have someone show you how, it will certainly enhance your boat handling skills. Although I have a bow thruster, I seldom find use for it as I use my rudders in conjunction with engines to get into tight spots. Oh and btw I consider my rather small rudders to be a detriment and would rather have larger but they work well enough for me to single hand my 53’, 62,000lb boat into most berths.

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Gotta agree with this. To say that one should ignore his steering is overstating it by lots. Sure one can do a lot with two props, but the rudders have their uses as well as stated above. Don't think I would go to the trouble and expense of enlarging or replacing my smallish rudders if I had two props though. Practice! My CHB is single with one rudder and its factory size which is smallish, but we manage with the help of the bow thruster, usually.

McGillicuddy said:

Well, I hate to throw a bucket of cold water on those who say you don’t need rudders to dock a twin screw boat but I would disagree. Use of rudders while docking greatly enhances the bag of tricks at hand for variable conditions including high current, breezy days and tight spaces. You will need rudders to walk a boat sideways into a berth. If you don’t know how to do this, have someone show you how, it will certainly enhance your boat handling skills. Although I have a bow thruster, I seldom find use for it as I use my rudders in conjunction with engines to get into tight spots. Oh and btw I consider my rather small rudders to be a detriment and would rather have larger but they work well enough for me to single hand my 53’, 62,000lb boat into most berths.

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Ditto. Except I don't use thrusters.

As they say, all boats are compromises. Change the rudders and what other handling characteristics will change?

I have run across a few that the rudders were all but useless at low speeds....usually boats with props in tunnels or pockets.

But the vast majority of twins, even with smallish rudders handled fine as twins, with or without using the factory designed/installed rudder.

For cruising, there are lots of singles without thrusters that manage,. A twin that is less manueverable is hard to imagine....unless single engine.

Maybe I need docking lessons rather than bigger rudders
Thanks all for the money saving tips !!!!!!!

I too use my rudders and twin engines. With bursts of power and use of forward and reverse (bow thruster too) the vessel can be walked sideways. We are blessed with big rudders which helps even more.

Rudder use and alternating engines is quite similar to how IPS and Zeus work, absent computer help.

caltexflanc said:

A little throttle burst will overcome lack of rudder size if you need it.

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Yes, but only in fwd gear.

Might enjoy reading about tow boats and flanking rudders or flanking doors.


Prop wash, prop walk, etc. Prop wash on rudders on aircraft is a topic also.


Those tows pushing a mile of barges don't have thrusters and they can walk sideways.


"Was told I need bigger rudders" This is a humorous title for a thread. Gives rise to a bunch of jokes and I can't quite put any together.

kartracer or anyone else looking to modify your rudder/s should very carefully consider the structural ramifications of doing so.

I changed the steering attach point on the horn where it attached to the rudder shaft to increase the swing to 45 degrees. The boat turns much much better but my whole rudder system is very heavily built. Even steers backwards w a little speed (2-2.5 knots) but I need to hold on to the helm very tightly to insure the rudder dosn’t slam over against the steering cylinder (no stops).

Rudders over 35 degrees should only be for slow boats. Slower than SD.

Cool docking simulator...

kartracer said:

Maybe I need docking lessons rather than bigger rudders
Thanks all for the money saving tips !!!!!!!

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Found this simulator...seems pretty realistic.


http://theboatdocker.com/

Riverguy said:

Yes, but only in fwd gear.

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Right!

The biggest obstacle to controlling a boat in reverse is thinking that the rudder will help. Once you overcome that thought and realize that, especially with small rudders, they don't help you to steer in reverse, in fact they may help more by being left turned what you might think is the wrong way, your control in reverse will improve.
For example:
If I am backing down a long channel, I usually can determine which side the boat will naturally want to swing towards. So I put the rudder over to allow a burst of fwd gear from the engine farthest from that side to push the stern out. Then I will have prop walk from the engine closest to the near side that, all by itself, is often all I need for that control, but I also can give a burst of fwd on the other side to help out. While controlling in this fashion, smallish rudders pointing to the near side, but without any wash against them, continue to do nothing at all, thus being a benefit.

One thing for sure...

Every twin boat model may seem compatible in handling, but not really and some may be at the opposite end of handling performance.

Handling barges and barge trains witn boats designed to do it, from my limited experience is nothing at all like small pleasure boat handling....hull design and horsepower ratios, plus props and rudders on towboats rarely look like pleaxure boats.

we had a 38 Lindell that we had the rudder area just about doubled. I didn't notice any change in docking or performance but did help when trolling for salmon. The rudders were stainless and the builder had the larger rudders in stock it was a common mod for the owners that fished the boat.

Riverguy said:

Yes, but only in fwd gear.

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So what? The objective is to move the butt of the boat laterally. And the emphasis is on the word "burst" which on a big boat yields minimal forward movement.

Youn should be able to do everything you need to do without touching the rudders or the throttles. Once that skill is down pat adding some rudder action can make things even easier.

Get away from the dock in calm conditions and practice spinning the boat with shifters only; notice how the boat moves with various combinations of shifting. Then back in a straight line again without rudders. If the boat turns a bit shift one side in and out of gear to straighten things out.

New boaters often stop the boat when docking instead of shifting one side to adjust direction or position. A stopped boat is not as easy to maneuver as a moving one.

One of the first things I teach is how to stop your boat and hold position in wind and current.

It is invaluable, especially in tight marinas where someone pulls out in front of you and you don't want to impale yourself on someones anchor.

I find it calming for a panicky boater who is struggling with docking, at least if they can stop and hold position, they feel in some control and can relax enough to try again.

I believe this is especially important with twins.

It seems to have been overlooked that the OP's boat is a lightly built, shallow draft vessel with extremely high windage and no keel. Sometimes you can't get there from here.

boatpoker said:

It seems to have been overlooked that the OP's boat is a lightly built, shallow draft vessel with extremyly high windage. Sometimes you can't get there from here.

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I just had a look at some pics of "Bluewater" boats. You're not wrong BP. They may need more than twins to be nimble when docking even if they had larger rudders. Maybe a good candidate for a big set of thrusters.

Bluewaters are houseboats and if they are like the one we had on Lake Powell they are squirrelly wind blown pigs at the dock! Thank God there was no tide or current on the lake: the wind was enough trouble.