How big of a Rudder?

Hacker Mike, 
If you go with a DK then you can ask for more sweep.  Not sure what the sweep is on the Orka but most ellipticals I've seen are fairly upright with low sweep.  If you get something that is more relaxed it will "de-tune" the reaction time and be more forgiving.  

One of my training partners ordered a 20  degree (standard) sweep DK for his swordfish, and at first had the same experience as you- found it too twitchy and made the boat less predictable.  After weeks of experimentation he figured out that he needed way less rudder input, and relaxed the toe angle so the pedals are more in line with the footplate.  With the mushy stock rudder the big rudder corrections felt great, but the DK has a lot of power so only tiny inputs needed.

He's going pretty damn fast on the thing now, just did something like a 2:41 in the 26 mile Maui to Molokai a week ago!

I had a great paddle last night. ~1.3m swell @ 6-7 second plus some smaller medium period groundswell. When the waves would merge it lead to some steep faces and awesome rides. 

I have a DK 9" 20° and agree with PSwitzer that a steeper rake makes the DK rudder less "bight-y" than an elliptical. If you hammer the pedals hard, yes, you do feel the rudder induced roll, but as soon as you let go, the roll dissipates quickly as the rudder self corrects. Also, I find the DK induced roll different than most stock rudders. It comes on slower and lets off faster which is reassuring

i can honestly say last night was the first time ever I've had multiple runs linked and surfed sets like a boss. I mean, I've linked a couple runs together plenty of times before, but the combo of the SF + DK rudder + a skilled paddler is a wave killer! The SF has enough speed to catch the run, although I found you really have to paddle all the way through the approach. In the past I would wobble or brace and even one missed stroke often means you miss the wave. Now I have committed to myself that I paddle onto the wave or capsize trying. So far this leads to 1-2 remounts per session but has meant I catch 50x more waves caught than in the past. 

Once on the wave, I have been refining my wave reading and predicting skills. I can see where the wave is going a lot of the time but occasionally I get burned and my hole turns into a peak. I do feel that the DK rudder (or other large, powerful rudder) is 1000% key to navigating a messy downwind, as intersecting waves create holes that must be caught quickly and if you cannot reposition quickly enough you will loose the hole. When Im near the crest of the wave if i give the rudder like 50-75% input, I can basically spin on a dime and hammer down to the new hole forming. Or for that matter now I can hold a nice diagonal line down the face instead of being pushed slowly towards a broach. None of my boats before the SF-S+DK had this ability (including the SF with the stock Fenn large elliptical rudder). 

So for me at least, the DK changed the boat for the better in every way.

i did a couple of rare flat water paddles last week and was going to change back to my elliptical but could't be buggered loosening two allen screws.  the DK is fine for my style of cruising and tracks beautifully.  my "reef buster" has been beefed up so i notice the slight extra weight when i carry the v5 and have to grip the side handle further back to compensate.  i hope that Don has some sort of design protection in place, because the glowing reports he's getting are maybe going to start the name brand ski makers doing some copying.  pete 

Don Kiesling's "gorgeous special edition rudder" (he called it)  arrived last week. See pic 3 below. And wow how gorgeous it is!! First pic below 15 degrees never caught weed but it was only a matter of time. Used this on my SES. Second pic my 20 degree big rudder for SEI and SR. Third pic the ab fab gorgeous new copper version at 30 degrees angle Don suggested. While we have weed issues in Perth from time to time - big blows and storms - my standard Stellar surf rudders and DK rudders have all been up to it. Nonetheless a few from here who've bought from Don had mentioned this so happy to try out the steeper angle.







DK absolutely the rudder man, this my DK No 5 across now four boats (selling three) with two standard DK rudders and  now three 10 " surf rudders  Found my new Nordic Kayaks Storm 61 to be corkey and poppy in cross-chop compared to my Stellar SR and SEI, and while the standard Storm NK rudder (pic below) has been fine, I wanted something to stabilise the boat more. 

Standard Storm 61 


And has the copper weed killer done that what! Significant difference now particularly in cross-chop off the sea-wall messy stuff which the SR would laugh at. (Interesting how a less stable boat improves your technique when you can't just get away with anything as you used to in a wider boat.) While I've had a handful of paddles since the rudder arrived there's only been one half-decent downwinder somewhere under 20 knots. Boat much more planted and much more stable out the back. Can't honestly say I've noticed steering and directional improvement, conditions just haven't been testing enough to tell. Not a shadow of a doubt however that the new DK will make this boat even better. Up to me to do the work now I've nothing to blame. (Well there's pacemaker but bide my time before I pull that one out.)

Hey Watto, Since you have a variety of angles on your rudders, which angle do you like the feel of most? can you explain a little? I just went with 20* because don said that was more or less a good middle ground, but I dont have much comparison for feel of a steeper or shallower angle. 

Also, what are the waves like on a "big but not standout" day? Here in southern california, id call a big but not exceptional day like 1.5m @ 12 sec swell with a 15kt wind and 70cm @ 6 second wind waves. When the wind is blowing 15+kt, the waves get pretty steep and break in open water. 
I ask because I'm interested to compare wave shape vs your rudder selection. 

"not exceptional day like 1.5m @ 12 sec swell with a 15kt wind and 70cm @ 6 second wind waves. When the wind is blowing 15+kt, the waves get pretty steep and break in open water.." 

That's a toughie MCImes, keen for any Perth paddlers to chime in here but I've no idea about our swell height and wave periods relative to wind. Ranga? However 15 knots here no-one would be bothered getting out unless starved for a paddle. I'll follow up and get back. Certainly can't see any waves breaking (or wind chop) here until low/mid twenties. Most paddling here 400-600 metres offshore coastal runs.

You asked McImes: Which angle do you like the feel of most? Can you explain a little? I just went with 20* because don said that was more or less a good middle ground, but I dont have much comparison for feel of a steeper or shallower angle. 

As Don pointed out to me in his response to my rudder request, extra sweep is for weed clearing however he noted there may be a reduction in response  - angle of attack (my words) moved rearwards ergo responsiveness reduction. My answer to your question: unless there's a weed issue, who you really need 30 degrees over 20 degrees? As per my previous  post I have not had weed issues so why now go big angles if not not necessary? My thoughts - we do get weed so what the hell - give the new angle a shot and follow DK's idea. Second point I'd make is I think this a boat/rudder relative thing.  

 

Very similar boat dimensions by numbers however look where Storm 61 rudder (my current boat) sits relative to SEI (my previous boat). The Nordic rudder, relative to my seat and boat rocker (variables) is likely to be more responsive being further forward. So depending on one's boat rudder, 'bite' is variable. Further forward the rudder is it seems the more immediate and strong response you're likely to get. A 30 degree rudder on a boat with rudder positioned further rear on one ski likely to be less responsive on a different ski with rudder placement further forward.

 Re our wave shape and rudder selection, we get a decent swell can be 3 metres plus, though seems messier (less purely downwind directional) compared to a Millers run. Here waves and wind generally over left shoulder that is a SW swell and SW / SSW or S breeze. When big it can push you around. In these conditions best for me is bigger rudder. To this point with limited downwinding on the new rudder I can only say tracks well in under 20 knot breeze (best paddling here 25-35 knots). Interested in other WA paddlers responses.

Excuse dramatic music but this clip sitting behind a mate is a reasonable day, bit choppy but decent swell:
johnwatson2.smugmug.com/Videos/i-Lbwp2rv/A. Next clip a big one gusting to 40 knots couple of years back - big rudder necessary that day!  johnwatson2.smugmug.com/Videos/i-Trgk582/A 

Tried to change odd code additions in there but no go. Rob?? (Last night)

All good  above - did some html fiddling and fixed.