If you have a rudder system that only allows full up or full down, you can't steer with the full up, and you may break your rudders with the full down when you are going through surf in shallow water. So you need something that allows an in-between setting; right? So what rudder systems work best for going through surf?

I know the Hobie system probably works, since surf is what the Hobies were originally designed for. But what OTHER rudder systems work?

Supercat......(ARC)

Okay, so how does it work? And can that system be adapted to other boats?

John Pierce has a cassette system where the rudders can be slip up and down in the casting vertically rather than pivoting. The advantage of this is that the rudder can be set partially down with good steering and no extra stain on the rudder or casting.

See: http://www.geocities.com/stealthmarine2002/t-foil.html

[Note the way the rudder can slide straight up or down within the castin--no pivoting. T-foils is a whole other issue...]

Downside is that they don't kick up. I think a system like John's but that can still kick up (as a safety feature) would be best for any sailing off the beach. I believe one of the new Farrier tris has such a system (but a lot bigger).

I like that.

If I can procure some extra rudder blades I might try that. (the t-foils)

good luck getting the angle right! what you need are adjustable t-foils like some of the skiff guys are experimenting with. The idea being downwind you can point the foil down to keep the bow high and resist pitchpoling at speed and upwind to point them up to get the bow down and the boat pointing well.

You engineers are to focused on getting it right the first time.... whatever happened to good ole trial and error huh?

Hi Mary,
None of todays popular boats have rudder heads that offer sufficient structural support to the rudder blade when the rudder blade is in the horrizontal or partially down position. The latest fad in rudder heads is an abbreviated design that offers structural support to the system when the rudder blade is in the fully down position only. These rudder heads designed for deep water starts only. Why did the builders change rudder head design? Ans. WEIGHT.
You can cut off all the rudder head framework aft of the rudder pivot bolt and save about 1 pound of rudder head weight. Now you have lost all structural support for the rudder in the partially up or fully up position. Why did all the rudder heads get broken at Jensen Beach a few years ago in the Worrell Race. Ans. No structural integrety in the system when the rudder blade is in a partially down position and used to steer the boat; no rudder head framework or casting aft of the rudder pivot pin.
Who makes a rudder head that does support the rudder properly in all positions? You know who....
Bill

Yes

I'd beg to differ with you on this.

I realize that my H17 rudder castings aren't made out of solid steel, but I've had to sail a good 5 miles in a stiff 15 knot breeze with my rudders up because my traveller broke and I wanted to stay within 10' of the beach.

While I wasn't all that sure that my tillers could take the force, the castings, which are 12 years old, did fine.

In fact, I'd wager to say that the boards would break before the castings. I'm not going to offer mine for testing though.

A big part of the problem in the Worrell is not just the lack of support for the blade. You can support it all day long, but if your boat is pushed backwards by the surf and your rudders dig into the sand.....well... something is going to break. Yes, the castings got split and rudders broke, but support throughout the rang of the blade (up-down) is not going to save you every time. I think I would rather see a casting or blade break before the gudgeons got ripped off. The construction of the blade also makes a big difference. Stock I-20 rudders don't have the strongest heads.

p.s. Dotans look really cool. I don't have any experience with them, but I understand Lamorak was doing well with them in the Tybee 5.

Okay, so none of them are any good. We all know that. So back to my original question. Which of them is the best for surf? We have to work with what's available. And we DO need rudders on our boats. So if you have to pick one of these totally inadequate rudder systems, which should it be?

And if the situation is so deplorably bad, why doesn't somebody invent something that works?

And, Bill, I know you are going to say you already invented it. But that doesn't do the rest of us any good if it isn't available on the market as a retrofit item for all of our boats.

P.S. About Dotans. They have the same problem I mentioned in the beginning -- either all up or all down, and no halfway for steerage through surf.

I have and use a modified Hobie system on my boat and think it works very well.

I think the Nacra system is the best for going through surf, but is not as good once you are out there. Notice that many of the HT's in the Tybee 500 had a knock off of this. However some had a different system that worked in a simmilar manner.

The stock Bimarre system is kinda awkward to work and probably tough to get down while trying to sail through surf.

I like the simplicity of the Inter system, but laks a little in the "beef" department.

The Prindle rudders lock down well, but getting them locked and unlocked was always my biggest problem.

For sheer elegance, you can't beat the Marstrom T-boat system.

Will R

I've sailed a few boats out there and I really like my Nacra system. I've never had the 'creeping' problem that a lot of folks complain of on either of the two Nacras I've owned (both have sailed for 20+ hours straight with the rudders down). I can put the rudders anywhere between fully up and partially down and cleat them. What I also like is that if the Nacra system fails, it fails in a full up (cam cleat failure), or a limp and floating position (bunji breaks). My Hobie 18 with the old style aluminum cams would fail to release from the locked downward position. It is quite a revelation when you come back from a day sailing blazing through the surf only to realize you can't release your rudders.

I really like the idea of the rudder that sits in a box and can be raised vertically up and down. You could make the box pintle points so they would break free in the event of an impact. I suppose the bottom of the rudder could be shaped in a sloping fashion so that when you are beaching you could release the hold down mechanism and let them raise in their trunks as they start sliding on the bottom.

Mary,
There is one readily available. I just didn't want to say SuperCat. It is a wide rudder head fore and aft with the rudder through bolt in the middle of the rudder head casting. It supports the rudder well at all angles. There is a green rope for GO that pulls the rudder down and a red rope for STOP that pulls the rudder up. The tiller stays fixed at all times for easy steering. You don't have to put the tiller crossbar up over your head and try to steer while coming down the face of a wave at the same time. Call or write Tom Haberman at Aquarius-Sail.com. There are probably pictures of the rudder head system on a boat at the web site.
BTW, the Dotans rudder head does not support the rudder blade when the blade is in the up position. There is no rudder head supporting framework for the rudder blade aft of the rudder pivot pin. The Dotan rudder system is a deep water start rudder arrangement.
Bill

Every pivoting system--no matter how stout and no matter where the pivot is placed--suffers from weather helm when not fully down. This can get pretty dicey to control. The advantage of the "cassette" system mentioned above (where the rudder slides up and down vertically, like a daggar board) is that if the rudder is partially down, the helm remains balanced.

How about the one on the Escape Playcat, I have never sailed it, but it looks ideal for surf as it is always down.

Are there any independant rudder makers other than dotan.

Eric,
I think the daggerboard-style rudder in a cassette sounds like a good idea, but a couple of questions/problems would be: How can it kick back if you hit something? And how much weight would it add to the transom?

The new Farrier 33 has this style of rudder, and it also has an optional kickback rudder sleeve. But on that boat the kickback feature can work because the transom is angled back. I don't know this could be made to work on a plumb transom. It's interesting to think about, though.

try this. I should really find a patent attourney!

This is a really quick and dirty 3 minute sketch. By controling your shapes and using composites, I bet I could make these almost as light as current rudder systems. The controls wouldn't be any more complicated than what we have today.

hey willr,how did you modify your hobie system?

Very good, Jake! Do you think it would be possible to have a cassette that would be versatile enough to use with a variety of different rudders? Rudders are pretty expensive items to replace just to get a different mechanism for raising/lowering. And most people want to have class-legal rudders if they do any one-design racing. If everyone could still use their stock rudders but just change to the cassette system -- and if the new mechanism could be made class legal, it would be much more marketable, maybe.

Just giving you a new challenge to chew on.

that was part of the reason I thought adding a slot in the center might help. It's not the ultimate solution but we could make a double sided plastic roller that would stick out of the sides of the rudder (kinda like frankenstein's bolts in his neck) and fit in that slot. One simple hole drilled in the rudder will do. They would take the majority of the frictional load and make rudder shape less of a problem. However, I'm not sure the slot could be made as long enough (it would need to be as long as the vertical travel of the rudder). In any case, something somewhere would still have to be shimmed to fit - I'll continue this thought next time I'm in my design office (the bathroom).

I literally have a folder with various toilet paper and restaraunt napkin scriblings in it! (was that too much information? )

still needs T-foils :P

Dear Lord in heaven, Jacob. I think I speak for everyone when I say yes, that was too much information; particularly after you mentioned a "quick and dirty 3 minute sketch" earlier. Mary, I swear I've never seen this folder and I'm afraid to ask where he keeps it.

Mary

Dagger rudders were mentioned here and I believe their features should be present in the ideal beach cat rudder. 49ers, 29ers and some Malcolm Tenant designs feature this kind of rudder. They are interesting for two reasons:

-The blade can be raised vertically in low wind or for beaching, reducing drag and draft but still allowing effective steering.

- The blade is totally removable, simplifiying replacements and maintenance.

The obvious and serious problem is that the blade does not pivot when hitting the bottom or floating debris.

My proposal is a pivoting dagger rudder - something that would do both tricks: pivot back and retract vertically.

Ian Farrier recently designed one for his F-33, and (correctly) called it kick-back dagger rudder. Unfortunately, his solution is not satisfactory for a beach cat, mainly because it relies on one attachment point only when kicked back - the upper gudgeon.

(It features an additional horizontal hinge in the upper gudgeon of the dagger rudder trunk, and a release mechanism in the lower gudgeon. When the blade hits an obstacle, the entire trunk and blade assembly pivots back, supported only by the upper gudgeon, which will has to support the extreme loads)

This design is very probably unsteerable after the lower gudgeon is released so it is not really safe for a beach cat, like most cats compared to the Supercat/ARC.

I was also dreaming of a pivoting dagger rudder for my boat because it has additional advantages in the particular case of the Catri (motoring in shallow waters with the engine on the rudder).

Then I remebered a very interesting daggerboard design from an old (10 or 15 years ago) windsurfer. As far as I know, it has not been used in rudders, but who knows... Anyway, I adapted that design to a rudder.

It is a simple concept and the rudderhead can be made as strong as necessary to please Bill Roberts, without oversized gudgeons, as in the F33.

The basic drawing is attached. The real plan is almost ready and I intend to use it when sailing in shallow waters.

I hope you like it.

Cheers,
Luiz

Looks great, Luiz! Let us know how it works when you get it in the water. It's not really clear to me how it is held in place when fully down so that it won't tend to kick back just from water pressure on a cat sailing at high speed, but I'm sure you have that covered.

Now you have given Jake something else to think about when he is in his design room.

Your rudder drawing shows potential, Jake! How would it suffice against those monster jellyfish at 20+ kts? Or maybe even a loggerhead turtle? In those situations, the rudder would be in the full down position. Would that place undue stress on the upper gudgeon?

I presume you'd control the depth of the blade with lines akin to the Nacra or SuperCat system? Who's job would that be while surfing down a 6'+ wave with the spin up?

Mary,

The line cleated in the kick-up camcleat keeps the blade upright - it is exactly the same line that brings and locks the rudder to the vertical position in the Laser.

When the blade hits an obstacle, the cleat frees this line and the blade rotates back.

The other line serves to rotate the blade in the other direction (to the back).

This control system with two lines is just ilustrative. For a beach cat, I think a rigid control bar (like the Tornado/Taipan system) would work better.

Also, control lines could be improved using the system designed by Bill Roberts, with spring locks released by the same lines - but the drawing would not be clear to demonstrate the concept.

The tricky part was finding an elegant solution to raise and lower the blade vertically. A tall rudderhead with vertical lines is obvious but ugly. And three or four control lines in a rudder are not desirable. Lets see who finds my solution.

now that's a beautiful thing Luiz! Wow. I'll process that more thoroughly soon.

I like Luiz's design, very much outside the box. The rudder would be very much vulnerable while halfway down. The delicate (thin) trailing edge would not have much support. I would think it easy to damage while inserting/removing it, or if you hit something with it halfway.

How would the blade stay in the half up/down positon?

My only other thoughts would be sand jamming the blade into place. Could you trust it in a Worrell style situation to "kick" up as you hit the beach?

Nobody else has addressed the thing I said earlier about the rudder getting jammed into the sand backwards, but if the blade was only half down, the likelyhood would be reduced.

I also wouldn't want to have to be in the back of the boat for a rough lemans style launch....gotta keep the weight forward.

sorry....rambling....

p.s. the mod Hobie thing...it tough to explain, you would have to see it.

I know of Luiz' idea, as I have a Mega Cat racing windsurfer (one design class) with this very daggarboard design. High aspect, variable angle with recessed well, controlled with your foot.

The only drawback I see is that in the "kickback" position, I would think there would be a lot more force on the gudgeon if you were trying to steer, and could possibly cause failure in that area.

I'm sure there is a way to work out the control lines so that you can secure the rudder in the down or mid-down postion. My only question is when my leeward rudder kicks back when I'm on the wire in a blow with the spin up. The I-20 system works mildly okay, as I just need to drive deep and push the tiller bar (which can occasionally be done from the center/windward side of the tramp. If I had to go to the leeward hull and fiddle with lines while I try to steer and my crew yells at me, I guess I could be in trouble...

And with that "T" rudder, if you are flying a hull, would that direct forces in the wrong direction? I can understand how it works on those Hobie Raves, since I think they don't roll (I think that's the term), but a cat pitches, rolls, and yaws...

Two years ago, I modified the cams on my Hobie 17 system, and it works great. This is not a new idea, but it solves the problem of the cam sticking down in the locked position, then the problem of putting the rudder back down. Simply cut off the top end of the cam, about 3/8 inch. This allows the rudder to be put down, with the cam in either position. It works well in the surf. There is still enough cam slot to hold the rudder down, even in a blow.

Caleb Tarleton

Jake,
If you want more details and a simple setup to move it up and down, please send me an email: sysfx@yahoo.com
Cheers,
Luiz

"Okay, so how does it work? And can that system be adapted to other boats?"

- rudders locked up in "park" ....release the line and they lay on the sand....start sailing out through the surf with them hanging down....tiller and crossbar are in the normal position unlike some other systems.....going through the surf they will not lock down inadvertently so you can't come back down on them.....once through the surf pull the rope and they become locked in. To release pull the same rope then pull the other one to raise them.


I don't see why they couldn't be put on other boats, certainly no problem bolting the whole system up to the back of the boat....may reqiure a little "sailor engineering".....great system IMHO

During normal sailing the forces in the gougeons are relatively low. Higher loads occur with the blade pivoted back. Then, higher loads are generated in this design due to the longer distance between the rotation axis and the gougeons. However, the load is divided between two gudgeons, while the F-33 configuration puts all the load in one gudgeon only - and still works (but not as a beach cat).



Not necessarily lines. A control bar is a good option. The tiller bar can also be used.



Agreed. If you are trapezing to the beach with the rudders down and your rudder kicks backs, I think you are in trouble regardless of rudder type...
For this specific situation the best rudder setup is the Dotan style - up, down, ready. Note that the Hobie and Supercat rudders are also problematic in the same situation. A pivoting dagger rudder would enable you to raise the blades vertically a bit before heading to the beach and steer the boat more effectively then with a pivoted rudder. An accidental kick back is... accidental.



If your concern is keeping a foiled blade down using a pivoting dagger rudder, the answer is that both lines holding the rudder in position need to be fastened to separate kick-up cleats (or the control bar should be held in position fore and aft). This will keep the blade down.

If your concern is about the contribution of T foils when the boat moves changing the angle of attack of the foils (due to heeling, yawing, pitching, rolling, passing waves) then it is very complicated and I don´t know enough to answer.

Back to the pivoting dagger rudder, in another post someone expressed concern that the trailing edge of the blade would be too exposed. The rotating axis is a plastic tube, free to rotate over the inner bolt. The tube has to be softer then the blade, to protect it. It can even be coated with ruber, if desired. Otherwise, the trailing edge is as exposed as in a non-pivoting dagger rudder.

Cheers,
Luiz

Why is it so important to have rudders that kick up, we have used the dagger rudders for 5 years now, first just standard blades, then with t-foils on. They work well and are easy but just different.

When leaving or approaching the beach, the rudders are lowered partially, about 8 ins, this gives as much stearage as a pivoting rudder half way up, but does not have the tiller loads of the pivoter.

Once sailing the rudders draw less than the daggerboards, so unless you are going fast backwards you will strike the daggerboard first.

No-one seams to feel that pivoting centreboards are a must but a pivoting rudder behind a fixed daggerboard will never have to take a hit unless you break the daggerboard.

As previously mentioned the main concern with all these systems is if the surf dumps the boat backwards on the beach, it's never happened to me so I don't know, but I think that if the rudder was only slid 8 ins down the cassette it would have a better chance of survival than a pivoting one.

regards


john

When you're sailing out through the surf you already have the dagger-boards up. You've gotta steer though so the rudders are down. A nice wave hits the nose, shoves it up high and pushes the boat back. Rudders touch bottom and, if turned, crumple sideways. If they were being held straight they likely damage the housing if not the transom.

John,

I don't know what boat you are sailing, but almost certainly what you wrote makes perfect sense for all boats sharing the following features with yours':

A) The rudder blades are exactly aligned with the boards AND
B) The rudder blades are significantly shallower then the boards.

For all boats sharing this design features, the pivot in the rudder is not so important and the dagger rudder is an excelent choice.

However, some beach cats don't have boards and in this situation the pivoting feature is VERY important.

Other cats have board blades nearly as deep as the rudder blades (ARC 21, for example). If the weight is in the back or there are waves, the boards will be shallower and the rudder can hit the bottom first. In this case, the pivot is also necessary.

Cats may also be designed with the boards positioned differently from the centerline (athwartships) then the rudders and/or inclined in relation to them. In any of this cases, the boards may just miss an obstacle that will hit the rudder - and the pivot is necessary again.

Each cat design will require different rudder characteristics, so there is no "best" rudder design. Each rudder design is best for specific global design purposes and each has its own pros and cons. The best design is the one that better matches the boat's design goals.

The Tornado/A Class/Taipan style is very light, so it is very good for racing without runing aground frequently. In light conditions, a dagger rudder (of equal weight) is even better, because you can reduce the wetted surface with less dramatic rudder aspect-ratio reduction.

For frequent beaching, a pivot rudder is necessary. I dislike the Hobie rudder because it is fragile and difficult to adjust, but it is easy to find replacement parts. The Supercat/ARC rudder is more resistant to abuse and more sophisticated - its only con is that it has more components (springs, bolts, lines, etc) to fail or jam - but they do not fail or jam frequently.

The pivoting dagger rudder mixes features (pros and cons) of pivoting rudders and dagger rudders. It is an interesting compromise for a dual purpose boat, suitable for speed and for frequent beaching. It is obviously not the best design for all cats, but it certainly works. And since it has never been used in cats (as far as I know), its features must be carefully examined before deciding for or against it.

Cheers,
Luiz

If I could have anything I wanted for surf, it would be the Marstrom design with the "hell for stout" construction of the NACRA or Supercat.

How about just popping the rudders up and steering via the sails alone? This should work long enough to get you ashore.

In my opinion the prindle setup is the best, once you modify it. Yes, the blades are a bitch when swept back, but there is alot of aluminim on the castings.

If you take the pull down, and pull up lines out of the rudder arm, and instead run them to a turning block over the tops of the transoms, you can rig a remote release and remote pull down that can be operated from both sides of the boat. And, best of all, you still have an emergency release should you hit sand.

So, if a blade kicks up, you can pull a line and lock it back down again. The prindle system works on a spring loaded notch that automatically locks in when the blade pulls down.

I had this setup on my p19, and it worked well in our area where we have a ton of weed. Without moving, I could release, dump weed, and pull back down again in 2 seconds.

I have tried this with other systems, and it does not work. Moving arm systems are very hard to remote because you have to pull the arms back and down. Forget it!!!

After breaking 3 ##$@@ blades on my tornado this summer, I am throwing the crap moving arm system away and installing a prindle rudder set. I want to be able to release and re-engage my rudders as needed, not when I can crawl across the boat and play with lifting the rudder arms, etc.

One last point. You almost always have to adjust the rake of the rudders when you transplant rudders. Be carful to make up some templates that show the exact rake of the existing rudders, before you take off the old set. When adding the new set, you will have to block out either the upper or lower gudeon, an align the to gudeons so that they are at exactly the same angle.

The best setup for each boat is not necessarily the same. The Tornado and A cat are not exactly beach cats - they are racing cats.

The Tornado system is designed to be light and is far from being the best for a beach cat. If you can, weight the Tornado parts after removing them from the boat and then compare weights with the Prindle parts.

But if you use the Tornado as a beach cat instead of racing, then the modification makes perfect sense.

Cheers,

One of the simplest rudder systems is the standard NACRA setup.
NO screws, cams, springs, or latches to adjust.
Just a single line to pull the rudder down and secure it in an ordinary clam cleat.
You can use either a bungee or another line to pull the rudder up. ( I preferred the second line)
The system can be easily modified to allow a single line to pull up (or down) both rudder simultaneously.
Since you only have to drill one hole, you could probably use any rudder that would fit inside the casting.

Who built your Tornado? Most builders use a unique rudder. From your comments it sounds a Reg White. In general Reg White's have trouble kicking up, Marstrom's have trouble staying locked down.

Mary,
Here are the basics on beach cat rudder heads. The pivoting rudder blade type rudder head has proven itself to be the most practical rudder up and down system for sailing off the beach, through surf, running aground by surprize, etc on beach catamarans.
For this type system to work well, the rudder blade must be submerged into the rudder head the same depth whether the rudder is up or down or halfway up or down. This places the rudder pivot bolt approximately in the center of the rudder head pivot chamber. This means that the rudder head is as wide fore and aft as it is deep vertically. With this rudder head framework, the rudder blade is well supported in the horrizontal position, in the vertical posion or anywhere inbetween. SuperCat, Aquarius Sails makes such a rudder head.
Today's so called 'modern boats' have gone away from the 'off the beach type rudder head' on their beach cats. Today's 'modern beach cat' has a rudder head with no rudder head framework aft of the pivot pin. This means that when the rudder blade is in the up position, there is insufficient rudder blade support. If you try to steer the boat through the surf or across shallow water,POW, you break the top of the rudder off or split the rudder head casting. This 'modern boat' rudder head design has eliminated the aft half of the rudder head support box in a weight savings effort. The net result reduction in rudder head weight is somewhere between one pound and one and a half pounds per rudder head.
Beach cat sailors down hear in South Florida don't appreciate this new design because we sail off beaches and sometimes a sand bar slips up on us.
The shortcomings of this 'modern boat' rudder head design were demonstrated very thoroughly at the Jensen Beach stop in the Worrell 1000 Race about three years ago. More than half the fleet lost their rudder steering systems in the surf due to broken rudder heads and blades.
Good Steering,
Bill

While I agree with Mr. Roberts on his rudder discussion, I would comment that the "Jensen experience" is rather atypical. Most sailors would not choose to launch in head-high surf with an onshore breeze (of less than 10 kts). The largest portion of damage was due to the boats "backing up" on the rudders - in this case, high aspect (deep) rudders.

From what I remember from that fateful morning, the sets were steep, close, and head on with a slight southbound current. The carnage played out as follows:

1) First wave either pushed boats back on their rudders (I'm sure this is not recommended with any rudder system) or kicked them on a broad reach.

2) Second wave flipped them (either because they had no steering, or were beam reaching and couldn't head up fast enough to drive over the next wave), and

3) Third wave pushed the boats on to their mast tips (with that characteristic "pop" noise)

Now, I know some of you out there would love these conditions ( [color:"red"]see JC's boat in the picture - keep in mind that the water is about 6-8 feet deep there [/color] ), but I don't really think any manufacturer could design something strong enough to put up with that punishment for long (and still be reasonable in weight)!

Mr. Waterbug:

Do you have a higher res. version of that photo?

Bill,

If it is not asking too much, I would like to know what you think of the pivoting dagger rudder concept. (attached)

It has the same blade area inside the head all the time, but since the pivot is not in the center, the stresses are quite different.

Thanks!

Unfortunately, I do not have this photo. It's from the Worrell photographer that year, so perhaps contacting Mike W. would help... JC's got a nice glossy of that photo at his house, with which he made that website photo...

A small consolation for all of the stuff they broke that day. Sort of like those Mastercard ads..

Broken masts (2) - $10,000
Swimming lessons for skipper and crew - $50

ONE BAD $SS PICTURE OF TEAM CASTROL GETTING THE SNOT BEATEN OUT OF THEM - [color:"red"]PRICELESS [/color]

Hi Luiz,
I don't like any rudder system that requires the sailor to pump the tiller up and down to raise or lower the rudder and at the same time use the same tiller to steer the boat. This is asking too much of the triller pivot point.
Bill

Bill,

What about the "variation on the same theme" in the attached image? It has no pivot point.

Luiz

Hmmm, how can you say it doesn't have a pivot point? It only doesn't have a pivot point in the light air config, where it also won't be any help if you hit something. In the normal config it definitely has a pivot point.

Hi Luiz,
I like this scheme better than the pump handle one but this one still has problems. 1. When the rudder is kicked up, the leading edge is 4 inches, or so below the keel; not good. It is still on the rocks or in the sand and mud.
2. For a rudder to be properly balanced, about 20% of the rudder area needs to be in front of a vertical axis passing through the pintles. 3. Ropes stretch, so the line holding the rudder down will stretch at speed and this will let the rudder swing aft slightly and the 20% rudder balance area is lost. A mechanical locking scheme works better with a breakaway spring system to release when grounding. What's wrong withg the SC system? It meets all functional requirements.
Bill

Keith,

Bill disliked the tiller's pivot point in the first drawing - not the blade's pivot. The second drawing has no pivot in the tiller, just the blade's pivot.

Re-read with atention the previous posts and drawings.

Cheers,

PS Also the leading edge of the rudder needs to be swept forward at least a couple of degrees, not vertical, to keep the rudder from 'ventilating' at high speed. When I took the first SCs to Hawaii, the sailors there went crazy over the SC rudderhead and how it worked. They said,'this works much better that brand X'. 'WOW, I really like it!'
Pull the green line for GO and the rudder goes down and locks. Pull the red line for STOP and the lock releases and the rudder comes up. If you run aground, the rudder automatically comes up. What could be simplier, Luiz?
Bill

I think he wants a system where it is easy to decrease wetted surface area for light winds

Bill

Thanks for the comments. I will try to build those features into the concept. Most of them are easy enough, but some may be difficult.

There is nothing wrong with the SC rudders, except that it is impossible to reduce the wetted surface without pivoting.

My goal is to have both alternatives available:

Pivoting for accidental grounding, other hits and fast raising AND vertical hoisting, for reduced wetted surface with the same blade section - a usefull feature for light wind sailing and better control in shoal waters.

As you know, I like to investigate new concepts, but in this case I am also trying to make a better rudder for my own boat.

It comes standard with a typical pivoting rudder, but with the engine bracket also pivoting in the rudderhead. This setup is meant to keep weight as far aft as possible, while also keeping the propeller clear from the rudder's foils. It also improves manouverability when motoring, so it is not bad. However, it will make departing/arriving in a shoal shore a bit complicated. The tilted rudder will be as inefective as a tilted beach cat rudder (worse, with foils) AND the engine will be out of the water.

By the way: I did not like the pivoting dagger rudder system used in the F-33. It is a cassete with a blade inside, held by two gudgeons. The lower gudgeon has freedom to disconnect from the cassete (if the blade hits something) and the upper gudgeon has freedom to rotate around the horizontal axis (pivot) additionally to the usual vertical axis. When it pivots, all the stresses go to the upper gudgeon ALONE. It is probably as reinforced as one would expect, but the concept did not convince me. I'd rather keep the rudderhead fixed and pivot the blade only.

Thanks again,
Luiz

Ooops.

Maughan

My ideal would be to couple the best features of the SC rudder with a vertical lifting blade.

Then, I would add a pivoting engine bracket - but for my boat only - beach cats don't need it.

Cheers,

Bill Roberts,

at one point you said
"Pull the green line for GO and the rudder goes down and locks. Pull the red line for STOP and the lock releases and the rudder comes up. If you run aground, the rudder automatically comes up. "

I agree this is a simple concept, and the SC rudders do this very well.

I modified my Nacra 6.0na rudders, much with the help of the pictures and instructions on the 'St. Simons Cat sailor' page. NOw there's NO bungy, so when it pops up, you don't loose all you steering ability. And it pops up when you strike something substantial, or run aground.

And about the line stretching and loosing rudder rake when underway, yea, that WAS a problem. Until, the advice of my good friend Scott Tuma 'Rigging Solutions' owner in Clear Lake TX.
NOw I use a very NON stretchy line for the downhaul line in the 'pivmatics', and when lowering the rudder, I 'seat the rudder against the casting. Then, with the pivmatic still up about two inches, I cleat it hard, then hold my thumb on it while putting it down on the tiller arm.

It works awesome now, and you have to 'uphaul' the rudders and cleat them like a prindle system. Never broke a rudder, or casting in the surf with this set up. It's easy to modify, and inexpensive too.

Todd Bouton

Hi Todd,
Wouldn't it have been great if the rudder system on your boat had come with the modifications you had to make to get it to work right in the first place? Wouldn't that have been wonderful!
Here's another benefit of the SC/ARC rudder system. If you need to sail out through the surf with the rudder part way down, half down for example. Pull the green line until the rudder blade is in the part way down position desired. Fold the green line around the end of the tiller and place it under your hand which is holding/steering the boat. The two abrupt 90 degree bends at the end of the tiller as the green line does a U turn at the end of the tiller will act as a temporary cleat while you are sailing out through the surf or across shallow water.
Good Sailing,
Bill

Yes Bill,

Without a doubt, the standard Nacra system, is in my opinion sub par, dangerous. As far as going over shallows, and with good bungees, you loose all your steering. And when the bungees get worn, backing the boat on catwheels often has the rudders folding under, or snapping off if you're not careful.

The simple mods though, allow sailing in shallows, as you describe. Yes the SC system is nice.