Rudder question for rules compliant DS1

[stillwaterfield]

I have a DS1 circa 1970. I have a DS1/2 rudder and a DS2/3 rudder. You can see images and descriptions of both of them for sale at DR Marine here: https://www.drmarine.com/products.asp?cat=119

In more detail: https://www.drmarine.com/proddetail.asp?prod=DS109
and https://www.drmarine.com/proddetail.asp?prod=DS132

When I look at the Specifications and Measurements section of the DSA Constitution and Bylaws it appears to specifically and in great detail describe a DS1 rudder. Is a DS2/3 rudder thus excluded for racing purposes? These are found on pages 7 and 8 of the document as found at Daysailer.org

I look at the new Daysailer offered by Cape Cod Shipbuilding and I notice the gudgeon bracket pictured for this boat matches the DS2/3 rudder.

Which of the two rudders may I or must I use to race in a DSA sanctioned race? Is the DS2/3 rudder legal on a DS1 boat?

[tomodda]

Hi StillWater!

Yes, as you'll see in the bylaws, the low aspect (fat) DS1/DS2 rudder is legal, the high-aspect DS2/DS3 rudder unfortunately is not. Remember. the basic premise of the class rules is to avoid an "arms race," everyone uses more or less the same shape boat and equipment. Hence the requirement to use the relatively slow fat slab of a rudder (as it's the original design).

That being said, there are a few things you can do to make the rudder less of a pig and possible more useful for getting you to weather. First and foremost, do something about the flat areas of the rudder and rudder head. You'll see that the top inch of so of the rudder presents a flat face forward, it's basically square. Round it off! Then you'll see that you're dragging the bottom of the rudder head (cheeks) through the water again with a square section forward. The only requirement for your rudder head, other than the obvious of not falling apart!, is that the rudder pivot be 9" back from the transom and not more than 1" above a line extending back from the bottom of the hull. I've seen rudder cheeks where they cut off a good bit of the "circle" of material below the pivot hole, leaving just a shallow arc. I've also seen aluminum rudder cheecks (with "speed holes"!) that end just below the pivot hole. All depends how much fiberglass cutting or aluminum fabrication you want to do.

Now, to be radical, you can make yourself a whole new rudder with a NACA foil. I believe GreenLake discussesd that approach around here somewhere on the forum, search for it. Haven't done it myself, but I also believe that making a new rudder makes more sense than trying to reshape your existing rudder into a NACA foll. What's the advantage of doing it? In theory, one more "lifting surface" when going upwind, and at the very least less drag. OTOH, seems more work than it's worth unless you are consistently in the first 4 boats of your local fleet. If you go that way, read up on the theory for the TRAILING edge. Modern thinking is that you want to square it off, and maybe even do it at an angle, leaving one side (port or star) longer than the other - all about forming good vortexes coming off your NACA shape. You certainly can go FAR down this rabbithole,... Spending your time learning how to properly read and react to windshifts and learning tactics probably has a better return on your investment than trying to shape that fat slab or a rudder, IMHO.

Well, that's my $0.02. I'll admit that every once in a blue, I stare at the RudderCraft website and dream. Then I take a look at my wallet and go back to enjoying my rudder as-is!

[stillwaterfield]

I looked at the Ruddercraft site and found a DS rudder here: https://store.ruddercraft.com/index.php ... uct_id=185
It's pretty, probably very effective, but not 23 inches from pivot to bottom nor 11 3/4 from stem to stern with a natural semi-circle curve at the bottom.

Wondering how THAT would be legal for racing in a DS.org race if the DS2/3 rudder as available for sale at D & R Marine isn't legal? What level and sort of mods are legal and what aren't?

For that matter I looked at a bunch of pictures at daysailer.org and for many of the boats their rudders look quite different at the top from the stock DS1/2 rudder also available at D & R Marine. Of course I can't see what's below the surface.

Perhaps I am more confused now than I was initially.

[GreenLake]

Well the first question is: do you intend to race your boat? The next question would logically be whether the race is under class rules? Many boats that you see in pictures are not raced at all. They are pure daysailers. Others may be raced in "beer can" events that don't strictly enforce class rules. That explains why they don't care about conforming to any bylaws.

In my case, the events I can make it to are of the second kind. However, in rebuilding my rudder I tried to follow the specs. They mainly affect just the blade. I think I managed to keep it class legal, but I never had the chance to get that confirmed. Key reason was that I wanted to use the old blade outline as a template to keep the build simple.

I didn't go out of my way to change the rudder head above the waterline. But I've since beefed it up a bit after an on the water accident showed a weak spot.

My aim was to fix the deficiencies in the original design that were not covered by the bylaws such as weight and foil profile, and to remove some drag. The secondary aim was to prove that I was able to do it without a lot of fancy tools or effort.

The write-up is here. Take a look.

[tomodda]

@stillwater:

>Wondering how THAT would be legal for racing in a DS.org race if the DS2/3 rudder as available for sale at D & R Marine isn't legal? What level and sort of mods are legal and what aren't?

It's NOT class-legal. If it's any consolation, the DS3 itself is not class legal, if I recall correctly. As for what mods are legal, that's easy - read Bylaw 3, section 6,

>>For that matter I looked at a bunch of pictures at daysailer.org and for many of the boats their rudders look quite different at the top from the stock DS1/2 rudder also available at D & R Marine. Of course I can't see what's below the surface.

Yes, covered by rule 6.7, "any convenience for handling of the rudder may be used." Basically, anything above the waterline is up to you, not controlled (as long as the pivot hole is legal). If it weren't for the weight, I'd be tempted to put a beer tap on the rudder head, perfectly legal! More to the point, you can save some pounds by modifying the rudder cheeks, is mostly what you've seen in those race photos. You're stuck with the underwater profile, fat blade it is. But the blade thickness is not controlled (Rule 6.1), so you can reshape the blade section to your heart's content.

As I wrote up above, you can REALLY go crazy with blade reshaping. What's better NACA 0009 or NACA 0012? Translating, 00 means no camber [symmetrical foil], 9 means the foil has a 9% thickness to chord length ratio: it is 9% as thick as it is long. So for us, our rudders can be 285.75mm MINIMUM (mm is easier for math), that's 25.71mm thick, 0.98 inch. NACA 0012 is 12%, so aprox 33mm, 1.3 inches, thick. Not much difference, but keep in mind that fat foils are more forgiving of ham handed helmsmanship. Meaning that they're more resistant to stalling, the flow reattaches to the more quickly afterwards than it does to more svelte foils. Though they do have a bit more drag. But you have a lot of drag anyways, that low aspect profile (is why I'd take the 1/2 inch thinner profile that Drawing 6.3 allows you).

Anyway, it all depends on if you are racing and how strict they are. The ultimate arbiter on any mods is the Class Measurer, who is on this forum - Bob Damon. PM him. But, as GL wrote above, if you're NOT racing, then who cares? Buy/Build whatever you want, and keep your old rudder to hand over to the next owner when/if you sell your boat. All good.

P.S. Dreaming... I've been kicking around ideas for a high-aspect blade rudder, particularly a cassette rudder: https://www.storerboatplans.com/foils/the-standard-storer-boat-plans-kick-back-dagger-rudder/. As always, there are tradeoffs, in this case you better make damn sure the rudder cassette (cheeks) is strong, those cassettes tend to split open. Also, they're less than ideal if you are ofter in very shallow water. I've only hit my rudder one in five years sailing (Centerboard hits first!), but you never know. Other than that, lots of advantages - lighter, simple blade to build, easy to adjust depth, automatically kicks back down. What's not to love? I'd love to give it a try one day, but need to find someone to fabricate the rudder cassette for me out of heavy-gauge aluminum, I don't trust my wood working skills to built a strong enough forward corner. Anyway, dreaming.....

[stillwaterfield]

Thank you both for the replies. Now I know better the bounds of any improvements I can make. The DS2/3 rudder I have is already an approximation of a NACA 0012 foil and seems to do nicely on the water. The DS1/2 rudder is very stock with no softened edges at all. The pintles are different on the two rudders, and so too the gudgeons, but I think I can harmonize them with a little tweaking and some new hardware and no serious modification. I could then swap out one for the other.

I have been racing in an open class at Branched Oak Lake north of Lincoln NE with the Lincoln Sailing Club. It's a mix of Sunfish, Snipe, my DS1, some other similar sized boats, an occasional catamaran, and once in a while some 22 to 26 foot boats. They are not at all purists outside of the Snipe and Sunfish fleets and we use Portsmouth ratings to adjust times. I'm not always last. In fact with a fixed up proper sized retractable keel now and some new to me Jotz sails I manage now to hold my own, If I get the hull smooth I might become competitive. Maybe. Thus my interest in a real Daysailer single class race somewhere some time soon. Just to see how I do within a single class of like boats. Do I need to invest in fixing up and improving the DS1/2 rudder? Sounds now like a good idea.

Sounds like step one is to reshape the rudder proper into something like a NACA 0009 foil while still keeping the exact height and length and curve and pivot point. Step two sounds like figuring out a stronger and leaner way to connect boat and tiller and foil together with 'some' leeway. I have a plane and belt sander and newly learned skill with epoxy. No skill yet with fiberglass though. As to the top I will have to see how I can strengthen and at the same time streamline it. I have already epoxied and varnished the tiller and it's looking super fine. I can figure out a tiller extension and a tiller clutch like I figured out for the DS2/3 rudder.

Thanks again for the thoughtful replies. I know not all races are going to require class purity. If they did I wouldn't have been able to compete at all yet. It's been a lot of fun so far. I had been just a day sailor up to recently, never racing at all. The racing has upped my game a lot.

[GreenLake]

Makes sense.

Alternative to shaping DS1 rudder would be to rebuild just the blade. Epoxy isn't hard. I like the System Three brand. They put out some documents with instructions. West System does as well. Read both. Key is to measure super accurately and to mix very carefully. That way it will cure guaranteed.

Always do a sample piece if in doubt and you should be fine.

Good luck also on the course.

[tomodda]

>>Sounds like step one is to reshape the rudder proper into something like a NACA 0009 foil while still keeping the exact height and length and curve and pivot point.

My humbly and earnestly submitted opinion: First step for the rudder is just get rid of the flat spot at the top of the rudder + cut down the cheeks+ make sure you are happy with the tiller and tiller extension. That'll do a lot to clean up the underwater profile and your overall handling while staying within class rules. Overall, for most "bang for you buck," work on your racing technique till you get to the front third of the fleet or so. Spend your "shop time" prepping your hull and improving your running rigging to fit your sailing style. Then shape your centerboard, maybe even building a new one. THEN worry about your rudder shape.

Digression #1 - there's an old story about René Lacoste - "Le Crocodile," Wimbledon and French Open champion, and inventor of the tennis shirt - where he wanted to show the younger players that you don't need a fancy racket. He grabbed a broom from the clubhouse closet, sawed off the handle, and beat all comers with just the broom head! It's the man not the equipment. Same goes for racing sailboats. At least up to the point where you are at the front 1/3 of the fleet amongst equally competent sailors. And then it's all about bottom prep...

Digression #2 - >>I have been racing in an open class at Branched Oak Lake... What a nice lake! Assuming that you have prevailing Westerlies, that lake is just PERFECT for racing, just put a pin buoy up at the end of each leg and the Committee Boat in the middle with a cooler of pre-mixed Martinis. Never thought I'd have Lake Envy, but there you go.

Wishing you fair winds!

[GreenLake]

All depends on your goals.

If your focus is strictly on winning your local races then your rudder slots into a longer list of priorities.

I didn't start with a rudder rebuild but when the time came to address those two weak points that Tom mentioned, I decided that I was more comfortable retaining the stock rudder as reserve. Not only to have a spare but to be sure I would have something that was class legal in case my rebuild didn't measure up.

I also felt that if. I was spending shop time it wasn't going to be on something half baked. I had tried to do a modest reshape of the CB already and learned how much time that took and how limited the result.

For lake sailing, local knowledge about wind patterns is key. On our lake I often manage to sail up to 20 degrees higher against competition that picks the wrong side of the lake. I guess I could steer with a paddle in those cases and nobody would notice. Which is Tom's point.

But there are other times when I'm glad I did the build. And it was fun.

[stillwaterfield]

One of my goals is to take the boat on a moderate road trip to race and sail with a bunch of other Daysailers. Not clear across the country like to Morro Bay (what a site) but maybe Wisconsin or Ohio or something. I'm not absolutely fanatical about racing. If I were, I would get a different boat or a different class of boat. But I have had some real fun with it so far. I'm pushing 70 so I know I have real limits. I have a few good years left in me if all goes well. Realistically I am just getting the boat ready for the next owner and I want to have it class ready. And to tool around on cool lake on a hot summer day, sometimes racing, often not. I have fun in the garage though working on this stuff, and that's part of it too.

I've recently gotten a wind indicator for the top of my mast, and telltales all around, and been able to capitalize on them. I discovered I had the wrong centerboard and did some mock-up new boards before modifying an old one to a nice NACA shape making a big difference in pointing. I got some crisp new sails and they want to fly and plane the boat. I now know the race starting process and can start with the pack. I know finally when I have the right of way so I don't always sheepishly cede it to others when I do actually have the right of way. I figured out my mast problem (too short) and have a solution for spring to get it taller so my jib hangs right. I've fixed the trailer with new big bunks. For the hull I have figured out how to safely lift the hull in my garage, and just figured out how to safely flip it singlehanded, so I can sand and fair it and paint it this spring before launch. It has not been in the years of my possession a slick hull at all. The rudder was a question of either selling the DS1 rudder as is or have a winter project of fixing it up. I actually like the DS2/3 rudder very much so I'm fine with it in a non-sanctioned race. But I do want the option of participating in a sanctioned race. Oh, and I have a ladder to install on the transom for those times I want to take a swim (scheduled or non-scheduled) and I want to get back on the boat.

I like the DS because it's big enough to stand up in and walk around but small enough to go single handed. Simple enough to understand. Capacious enough to carry camping gear for multi-day journeys or to have guests over to watch fireworks from mid-river. Easy to trailer and everybody says they like the look of my boat.

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