Sailing the Hobie 16 upwind with a rudder up

A lot of the Ricans, Mexicans, and Aussies are sailing Hobie 16s upwind with the weather rudder up. The idea is less wetted surface area AND less drag from whatever part of the weather rudder is in the water.

Initially, I started wondering...I mean how much are they really saving? What with all the hassle of bringing the rudders up and down in the middle of a tack. It just didn't seem worth the little bit of gain you might get. (Of course, you do get bonus points on style cuz it looks bitchin'!! )

I was sailing along one day, in near-perfect sail trim so the boat was balanced. I started looking at my weather (EPO) rudder, and sure enough, there was a huge air bubble (aka cavitation) along the weather side. I jiggled the rudders to reattach flow. That worked...for awhile. And then the cavitation reappeared.

I've been gun shy to try raising a rudder upwind because it means you spend more time in the middle of the tack (having to fiddle with rudders and all). But after seeing that mini-cavitation, I am beginning to rethink the merits of raising a rudder upwind.

Oh, and by the way, this only works when trapped out (when your weight is aft and loading up the rudders)! We tried this in lighter air while on the tramp. You know, with the weight forward and OFF the rudders. Doesn't work!! You lose all kinds of steerage and really look stupid!

Peter, Peter, Peter, I think you need to spend some time reading the "Test" post.
It's to early in the winter for such serious issues. <img src="http://www.catsailor.com/forums/images/graemlins/smile.gif" alt="" />

Anything over five lines of text and we glaze over.
(At least that is what i read earlier in a post)

I have sailed with one rudder on the upwind for many years and I start doing it from single trapeze and up. I seldom start with one rudder, it's to easy to stall if you get disturbed air. During the tack you don't lose much when going into the tack since you do a "roll tack" by spending time getting the rudder down. But you lose a bit when you start sheeting in on the new tack because you have to gain speed until you can raise the rudder. The option is to jump out in trapeze with both rudders in the water and then kick the rudder up with your rear foot and lean in and get it up from the water.

Another advantage is that you can trim the rudders close to parallell to optimize for the downwind and keep both rudders in the water on the downwind. I have capsized a couple of times trying to get the rudder down before the gybe!

/hakan

Your points of the extra time needed to complete a tack and tack the rudders is a good point. I have a P19mx and a TheMightyHobie18 and I do not tack the rudders. The Hobie has an excellent rudder casting design on the H16 but I have found on my TheMightyHobie18 that if the rudder cams are not in perfect shape the cam does not release properly and the result is you can not lock the rudder down the next time. This really screws up the boat handling until repairs can be made, this takes time you do not have in the middle of the race. The Prindle rudder casting is alot harder to manipulate and I just do not even think of tacking rudders. It sounds to me as if you have not aligned your rudder system properly. (or your boat is too limber/loose) Rig the boat w/sails up, sheet the sails in and then measure you blade alignment I set mine with 1/8" of toe-out because when I release the mainsheet the blade alignment goes to neutral for downwind sailing. Also wet sand your blades: 220 grit ...320 ... 400 ... 600,800,1000,1200,1500,2000 ... and (finally)2500grit. You can find this sandpater at a Body Shop Supply house.

I fill my rudder cams with "Marine Tex" on the hollow side to make them solid, they last alot longer. I'm waiting for someone with a CNC milling machine to machine them out of solid sheet teflon. That would be a big improvement since the current cams are CHEAP pieces of plastic and sometimes don't even last one day!!!!

Basic Racing Philosophy: The shorter the race course the more important it is to have the boat going in the "right" direction and worry less about the small tuning adjustment to the boat. This is assuming the boat is reasonably close too being "properly in race tune/trim"

HMurphy,
I think Peter is looking at the technical aspect of the question. I think he is familiar with the details in your post. He is pretty obsessive about all of the little details on his boat already.

Congratulations by the way Peter,
51st in Finals Hobie 16 Worlds & 10th in Masters Hobie 16 Worlds

Hey Peter,

I watched these guys pull off the raising the rudder maneuver countless times at the North Americans. They released windward rudder, tacked, and had the new windward rudder up in about 2 seconds. It requires a flawlessly working rudder system and the choreography of a highly trained dancer to be successful. As with a lot of the different aspects of competitive sailing, I think your gear is second to simple practice, practice, practice.

Whatever these guys were doing was working quite well at the NACs!!!



Img: Valeske.

I also have been using this technique for a few years.I really like the feel it gives on the helm.The other positive is it forces you not to pinch.

At the 2004 worlds someone asked Gavin Colby why he did it and his answer was "because it looks f*cken cool"
I know there must be more reason behind it but is it really worth it?
I know your looking for more of a solid answer, but i've also found on older boats you can't trust your cams to function enough to be able to unlock and relock all the time.

All very good points, Murph. I wouldn't think tacking the rudder on an 18 would be that critical. Since you are getting lift off of the daggerboards as well as the leeward rudder, I would think that would take some of the pressure off the weather rudder.

As for Hakan's idea, whenever I have tried lifting the weather rudder while at full speed, I have been unsuccessful. The rudder is too loaded or something to pop up. Doing so from the wire sounds even more difficult.

Mike Madge just emailed me to tell me he (Hakan) keeps his rudders real loose. Maybe that will make a difference. I will have to experiment this spring.

The Marine Tex idea on the cams sounds interesting. I would have to see if it is per class rules. What do you do? Do you fill in the hollow when the cam is locked about 1/2 way? If so, does it make the rudders kick up easier (and inadvertently)?

That is/was the whole point to this thread. I think it depends on what level you are sailing at. At the local, club level, it probably isn't worth it.

But in big fleets, NAs and Worlds, I am now of the belief that it is worth it. I mean, for years people didn't raise a rudder going downwind. Now it is a given if you want to compete in A-fleet at the local level and above.

It's like Jeremy says, practice, practice, practice. It definitely ain't the equipment. When I first saw the technique I thought "they are going to wear out their cams so fast"! And they probably do.

But at the level of sailing we are talking about, $14/pair (per Hobie catalog) is a small price to pay!! In fact, this "rudder up" technique freed me! I used to replace cams every 5-10 years or when broken (usually the latter!!). Now I replace them every 2-3 years, and may start doing that sooner.

That is a whole new thread -- the way sailors, particularly Hobie sailors -- refuse to replace cams. Rudders have to be one of the most important systems on a catamaran, and they compromise that system significantly by refusing to replace a $14 part. Don't get me started!!

The single most important thing in keeping everything working well is keeping the cams and plunger greased up, and free of dirt and sand. This has been beaten to death on this forum and the hobie forum.

Actually it was Gavin Colby that said he keeps his rudders loose.This rudder up technique is more suited to big bodies of water with steadier wind.On inland lakes with lots of shifts it is easier to get caught with the boat pinching.Pinching with one rudder up is bad news.

Peter,
With binoculars I watched the WC's in Mexico going to weather in the finals (winds were double trap,traveler centered, a rudder up).
The skipper had one foot on the back of the crossbar, and the other foot was on the hull about midway between the rear pylon and transom.
(crew further back next to skipper)
They started in the middle of the line, and with the weight that far back drove over the fleet, and won the race.
(while the rest of fleet had the skipper on the crossbar only)

SWAG, the weight that far back may alleviate some the weather helm, and increase the steering sweet spot, and the rudder does NOT stall out as easily.
I wonder if that anyone steered from that position in Tahiti?

I skuff up the inside of the hollow with a Dremel tool and then fill up the hollow side with MarineTex. I then sand the excess off by rubbing the cam on a piece of sandpaper on a flat surface. Then I install the cams in the rudder casting using the "amorphic studs" you can buy at the Hobie dealers. I keep a spare "fresh" set with studs ready to go with my spare parts. If I need to replace a cam during a regetta it only takes a few minutes. Racing in Jersey bays, with sandbars everywhere is really hard on rudder cams! look for the SLIGHTEST deformation in the cam, particulary the hole in the center "boss" and replace it. The previous comment about sanding the blades comes from Fluid Dynamic: Low Reynolds Numbers/Laminar Fluid Flow Theory. The smoother the surface any fluid is flowing over, the less likely it is to become turbulent and delaminate from the surface. this can cause what you are calling cavitation. What I'm trying to say is that if it is smooth enough, the blade will produce so little drag so as to make tacking rudders practically valueless vs the time to tack the rudders and possible system failure of a cam not rotating.

This will sound crazy but carry a (thin)putty knife on the boat. To fix a Jammed" cam simply place the putty knife vertically between the casting and the cam and press down on the plunger with the putty knife. Rotate the cam with your other hand into its proper position.
Good Luck

Great idea with the putty knife. The main sheet works well too, but only if the cams are in good shape.

One the other hand, filling the cam would probably not fall under the "class legal" category. The basic rule in the Hobie Class Rules is, if it's not in the Hobie Class Rules, it's NOT legal. I'm not going to spend time digging through the book looking for this, but if someone finds a rule that would allow this, let us know.

Mike

Interesting thing with the weight distribution when sailing with one rudder.

After a tack I begin with crew and skipper far back in trapeze but when the sails are sheeted in and the boat has gained speed we move forward to push the bow down. In higher waves we move back a bit to avoid pitch poling, I've done that on the upwind.

If we get into a stall situation we move back fast and release the main a bit, usually the boats bears away and you can sheet in and move forward again but sometimes you get stuck and lose miles!!!!



/hakan

This is the quote from the general rules section:
____________________________________________________
7. DESIGN FEATURES AND APPROVED CHANGES Nothing may be changed or removed from any Hobie Cat that will in any way alter the structural integrity, design function, or built in safety fea-tures of the boat. All changes shall have prior written approval. Provided they do not change the basic design and configuration, approved changes are: stronger gudgeons; stronger pig-tails; larger diameter wires and running rigging; reinforced flanges not affecting water flow. Except as allowed in these rules, any changes or additions that in any way can be construed as speed devices are not class legal.
____________________________________________________

I think this would be considered strengthening existing structure rather than a speed device and therefor legal.

The winds in Fiji were mostly 8-12k with a few races above that. But it was very flat water, and the weight, when it was on the wire, was not in the backseat.

I know the Aussies trapeze very far aft. In Cancun, where it was a very mixed up sea from the hurricane, sea breeze, and tidal breeze, being back was probably the place to be. I don't know because we were too far back to see!! <img src="http://www.catsailor.com/forums/images/graemlins/frown.gif" alt="" />

As cool as the "cam filling" idea sounds, I don't want to risk fouling out on it. I have emailed Mal Gray (rules committee rep) twice questions about a 17 I am rigging and was shot down on both ideas. Granted, those ideas may have been a little more creative than the cam idea, but it isn't worth the risk. Thanks, anyway. I'll keep it in mind and maybe email Mal and get his take.

Hakan, I appreciate your comments about getting aft when coming up to speed. My crew and I will experiment and work on that. As for moving the weight forward, I don't like that. The bows start punching in. That is slow.

Murph -- my blades (which were admittedly the old EPOs) are sanded to either 400 or 600 (I can't remember) with wet 'n dry. They are smooth. The cavitation I saw on my weather blade -- DURING BALANCED SAIL TRIM -- was a thin bubble over the surface of the rudder approx. 6" wide and approx. 8-10" long. I use nearly neutral helm.

I think it comes down to what Jeremy wrote earlier -- if you practice it enough, then it is as basic as any other maneuver we do on the boat. Just gotta practice it!

It is pretty easy to see just from this thread that the ole saying "he who puts the most time in on the water, wins" certainly stands true. The only way to find out what really works is to get out there and try it...over and over and over.

Hi Peter,
I use "old" EPO's on my boats also, until the introduction of the new EPOs nothing was as good. I am very protective of my EPOs, because I can not afford a set of those new beautiful, wonderful EPOs. Anyway, use wet/dry sandpaper all the way to 2000 or 2500grit and then polish with a buffer and polishing compound with lots of water. Testing has shown that you can not get too smooth. Try sanding a small section of you hull to 2000grit and then spray it with a water spraybottle, watch the water beads ... compare it with a section sanded only to 400grit .... The section sanded to 2000+ will not "bead" but will just run "dry" with no beading. To develope a water bead you need a surface with some slight friction to develope surface tension and produce a water bead. No friction ... no bead!

Many of us have cut off about 3/8 in off the leading edge of the rudder cam. The rudder will still lock down, with the cam in the up or down positon. No more worry about cam position.

Caleb Tarleton
H-17

What other secrets are you hiding from us, Caleb?!!!


In Fiji, the Aussies had actually ground down the round, convex part of the upper casting so it will mate better with the round, concave part of the lower casting. They claim they are getting even more rudder rake.

I am waiting on a template, but nothing has come through yet.

I'll buy that. I was zeroed in on the "Loophole" rule. But, there are other rules that basically say if the change doesn't directly improve boat speed, it's OK. Not sure I'd want to go to the room over it, on either side though.

Mike

I like this explanation.