Tag Archives: myo kayak rudder

Seawave Rudder MkII tested

Gumotex Seawave main page
Rudder rationale discussed
Gumotex’s 2016 factory version
Making the prototype rudder
Testing the prototype
Update 2019:
I’ve not used my MYO rudder since I made it in 2016. Partly because I’ve only done day trips predicated on nice weather, but also it’s all just more faff and clutter, not least the lines and footboard. As explained earlier, for gumsee07multi-day trips where you must deal with the winds you’re given, it’s a good idea. But even then, you only notice your relative lack of speed alongside others. Alone, you’re as fast as you are.
Rudders are not about steering or tracking as they are on powered boats; in a kayak they’re about enabling a more efficient, balanced paddling effort on both arms by compensating for the boat’s deflection for side winds. In a way the simple stock skeg-shifter (right) will do as well with much less clutter and weight. Or, use this rudder, but locked in position as an ‘articulated skeg’ in place of the Gumotex skeg for shallows and beach parking. That is handy to avoid stressing the stock skeg, especially when the boat is loaded. 

mullamulamap

While waiting for rudder bits to turn up, we went out for an evening paddle round Eilean Mullagrach. It was pretty calm but at no point did I think, ‘Darn, I wish I had a rudder’. When it came to turning corners we just paddled hard or dragged a blade and round we came.
But the Seawave rudder project carries on like a supertanker with a jammed… rudder, if for no other reason than it’s fun to experiment and a rudder can also work as an articulated skeg when locked out – something I may look into when it’s all done.rudderdyl
Ironing out the flaws with the prototype added up to attaching it more securely at the back and making the pedal board out of something more responsive and durable. By coincidence, all these components can be sawn from a single piece of 450 x 300 x 12mm LDPE chopping board (left) which costs from £8 on ebay in a range of colours. This is 50% thicker than the smaller board I used on the prototype plate so doesn’t need doubling up and gluing to make it rigid.
rudm211rudm21At the back I  slimmed the rudder plate right down to a simple strip of 65mm x 450mm, glued a block on the end to better support the gudgeon swivel pivot sleeve and added the crucial second fixing under the portaging handle (left). I also added a triangularish screw plate rudm23underneath (left, with red cord) so it all sits snug in the stern. With the hardware and saddle strap that now adds up to 306g (the rudder unit weighs 450g with its running lines). Even though it’s slimmer than the proto plate, it weighs about the same because it’s now 12 mil. But looks a whole lot neater.
rdd5The pedal board is from the same slab but uses stainless hinges, not zip ties. I’m reminded, you’re constantly making small adjustments as you paddle so pedals need to be as taut and responsive as possible. Once I’d trimmed the board and pedals a bit (left), with hinges it came in at 660g.
rudnee1The board and maybe the pedals could have been made from 8mm if there was some to spare – but an 8mm board wants to be ~450mm wide to sit snugly in the boat’s side channels. Like the rudder, the pedal board will be subject to strong forces in heavy seas so also needs to be solidly jammed in. Meanwhile, I noticed the floor-laminate prototype  board (right) gained nearly 15% in weight after getting wet – a sign it won’t last long. Still, it made a good template.
garbpedalsI do wonder if something like the Grabner rudder pedal bar (left, similar to Gael’s old H2) would be much lighter, as solid and as effective as my board. It costs €70 plus €30 for a pair of Zoelzer pedals.
I can’t really see how I could replicate that alloy footrest bar – out of copper tube filled with resin perhaps (like this motorbike rack)? It’s held securely in place without fittings by being jammed in the channel cavity between the floor and the sides (like my board), but a check with Gael advised me against it. As it happened, I’d pretty much decided the same mid test run (below). A sliding ally bar plus sea water isn’t a great combination and might bend or break, or the pedals snap. I know the ally backrest bar on my Amigo wasn’t up to it and Gael’s backrest broke (though it was ancient). My plastic version may weigh double but should be solid. Interestingly, just as a bag of clam cleats turned up make a quicker way of fine-tuning the rudder pedal lines from the cockpit, I see left that Grabner use them – a good sign.

rudhorserudm221The weather here’s about to crack and then we’re moving south, so in a rush I took the revised rudder plate out for a test with the creaky waterlogged pedal board. Heading towards Horse Island tidal passage, I didn’t need a weatherman to know which way the wind blew: from the WNW at about 12mph. Initially the boat needed constant small corrections to maintain a course, and there was some stiction, hopefully down to the zip ties on the soggy pedal board. I tried a few pedalotight turns and marvelled at the control and how sharply the boat swung round like a pedalo. The rudder plate is now as rock solid as anything fitted to an IK can be. Again, I consciously tried not to correct with my arms, just my feet, which were twitching regularly.
rudm24At Horse Island I was way too early to run the passage, but as it was probably my last paddle here till next year, I decided to head for Badentarbet. Turning north, closer into the wind the micro corrections were no longer needed and the boat ran as if on a skeg, but without arm corrections. I’m pretty sure paddling 20–30° off the wind would have required arm steering, but I just hacked away towards Rubha Dunan on the mainland as the wind increased. When I tried a bit of downwinding protracted rudder juggling was needed to keep the back-end in line.
rudgaprudm23I passed through a channel on the headland and the NW wind got steadily stronger so crossing the bay to the beach seemed to take ages of effort. By now the small corrections I’d been making were no longer necessary, perhaps something had bedded in, the knots had tightened up or like riding a bike I’d just got the knack of minimal rudder movement to keep the boat on track. But upwind paddling is comparatively easy so I tried across the wind, now running over 15mph, and a bit more downwinding which gave me that unsettling Ningaloo feeling. This must be the weak point of a buoyant, windprone IK (especially when unloaded), and maybe all kayaks and canoes too. The chop was only a foot high, but were there a swell of a metre or more, the rudder would be briefly lifting and the stern sliding. I wonder if in a such conditions a combination of rudder and skeg (which is always submerged) might be a way of limiting weathercocking? Or perhaps just more practice is required. There’s also another solution that might arrive here in time to try out.
rudruddAs I neared the beach the wind was hard in my face but I realised I was actually on good form, unlike on the Tanera run with the prototype. So I hammered away with all I had until my strake hissed onto the sands. Paddling hard is all helped by my brilliant, bent-shaft Werner Camano paddle, no less than ten years old this summer. It still clips rudaliotogether with a satisfyingly ‘clunk’ and has very little play. If it ever got lost or abducted by aliens I’d buy another without hesitation.
I was glad I’d got stuck into a longer test run than planned, and am now confident my MYO Seawave rudder is in the ball park. Hopefully the new pedal board will complete the job. 

  • Total weight: 300g rudder plate + 450g rudder + 660g pedal board + ~100g rigging = 1.51kg (3.3lbs), or < 10% of the boat’s weight
  • Total cost MkII version: £20 rudder + £15 rigging + £8 LDPE board + £10  hinges + £2 fittings = £55

rdd4rdd2For about £200 posted I could have installed a 2016 Seawave rudder kit, but from all the images I could find at the time it was unclear exactly how it secured at the back – there must be their version of an unseen triangular underplate, but even then it’s still a stressed-out single point attachment. My additional under-handle fixture eliminates pivoting. And the plywood Gumotex footboard (right) gumrud3appears to sit loose and seemingly will also pivot on that single strap. Production versions may differ and let’s not forget that adding all this complexity also adds a risk of breakage or damage. The simplest solution is usually the best, but the 160-g skeg will always be clipped in the boat as a back-up and a Seawave is controllable (if much slower) with no tracking aids at all. It’s worth remembering: a rudder isn’t about day-to-day tracking, it’s about maintaining a course when the boat gets pushed about in stronger winds. In such conditions a skeg is essential and a rudder is an improvement, as explained here.
rudstashrudderweightsOn the beach, prior to lugging the boat over seaweed-clad boulders, it took only 30 seconds to unclip the rudder mechanism from the plate to pre-empt stumbling and damaging it. Since then I changed the rudder plate mounts with tool-free knobs and an eyelet (left). When rolling the boat up it was best to pivot the rudder plate around the drain hole 90° to pack better.

rudm25

Seawave – Oh Rudder, How Art Thou?

Seawave main page
Skip forward to MkII rudder

ohruddaWithin hours of finishing my prototype rudder I set about finishing it properly, and after a test run to Tanera, made further improvements, listed below, before trying it again.
The whole set-up wants to be mountable/removable without any tools or knots to untie. I used mini karabiners to attach the various lines but snapsrealised snaplinks with a ring are better, as they’re permanently attached so won’t get lost. I recall the fine wire clips on my Incept rudder and after hours of webbery found out they’re called fishing snaps (right). Let me tell you, you can spend a lot of time online trying to figure out if size 00 is bigger than size 8 and still end up buying ones so small you need tweezers to open them. Moving on, some ringed karabiners (black, right) now do the job.
rudd01rud71I only know two knots from my climbing days and still regularly use the Figure of Eight, (right and left) a quick way to put a loop on the end of a line that’s easy to undo. If you want to feed an Fo8 into a fixed ring (like the black krabs, above), just make a loose ‘8’ near the end of the line, then feed the loose end through your ring and follow it back in and around the Fo8 all the way out again. And add a lock knot for good measure.nips
Lines shouldn’t be knotted directly to a fixed object, especially if it’s pivoting, but on the rudder’s lifting pulley there’s no room to attached a krab or mini shackle. The lowering pivot has a hole and channel for a nipple (right). I suppose I could track down a short length of appropriate wire cable, but for the moment it’s a job for our good friends, the zip ties. Lovely family. I also moved the rudder lifting knob to the right side: forward to lift (slightly more effort); pulling back to drop seemed intuitive.
rudd03tanrudIn this pre-optimised form I crossed the two miles to Tanera Mor with a light WSW wind at 2 o clock. First, like a bush pilot, I checked my flaps: up and down, left and right, then started the engine and pushed on the throttles. rudd07
Very soon something was wrong. I was having to rudder hard left and the pedals were leaning way forward. I stopped to knot the lines to take up some slack, but still the boat was turning into the wind and the rudder was very slow to respond.
rudd06With a skeg it’s usually the bow that pushes round on a crosswind. Was the new rudder assembly making more windage to push the back around? More stopping to add knots to the pedal lines. I was also reminded that with a rudder you don’t just set it and paddle away, but are constantly making tiny corrections. You probably to the same with your arms and a skeg, but never notice until it gets obvious (the whole point of fitting a rudder). For this reason a rudder wants to be as smooth-running and taut as possible.
rudd11The forecast was cold and northerly, so, over-dressed in a cag and dry pants, all this foot and arm work took it out of me as I resolutely tried not to correct with my arms. It was a relief to arrive at Tanera’s 200-year-old pier. Mooring up, I noticed my rudder plate was dislodged (right), explaining why the pedal rudd10tension and tracking had gone awry. It was only when I got back that I noticed I’d fitted my nutted ‘underplate’ upside down and the nut had pulled out. Oh Brother What a Plonker. I locked down the plate with a zip tie and readjusted the pedal lines yet again.
rudd05It was also clear that my scrapheap pedal board was flawed. Heels resting on the board (left) put them two inches higher than normal – not good for paddling efficiency, comfort or pedal actuation; perhaps quite good for neglected muscles. That was easily fixed by turning the board around.
After an  hour exploring this historic corner of the island (more here shortly) I headed back and immediately noticed a much more responsive rudder – now you’re talking! It was like driving with all the wheels done up tight. rudd38Lower heels gave a much better angle on the pedals and I noticed I was now operating the pedals with the outer edge of my feet, as I recall on the Incept. Line drag was minimal but now the wood laminate pedal board creaked and the zip tie hinges were a bit mushy too.
imboredI’d already ordered another slab of LDPE chopping board to make a pedal board out of something more water-resistant than compressed dust, as well as the extravagance of proper marine-grade hinges (well, that’s what it said on ebay). I tried a quick bit of disc sailing too but it wasn’t really windy enough – more on that later.
rudd42As I neared Badentarbet beach the g-friend happened to swing by and, showing her some moves, I  was amazed how sharply the boat could turn at low speed in the shallows, almost like a handbrake turn. Of course that’s not a particularly useful rudd04attribute in a kayak unless a WWII mine bobs up in front of you, but it’s good to know it worked. I also got a chance to test my newly bootied Kokotat dry pants – they worked like they should, too.
Back at the house, I realised the pedal lines had been cut before considering the need to move the pedal board forward for tandem paddling. Luckily, more Dyneema turned up next day, so I re-used the former yellow cord for the rudder lifting lines and ditched the saggy red paracord. Much tauter action.
rud61The wheeled cord locks turned up too (right). I had a suspicion they wouldn’t work for adjusting rudder rud62lines and I was right. They need tension from the same direction while snugged up against the edge of a stuff sack or something. I tried doubling the lines with two pulling the same way but the rudlokred Dyneema is too thin, hard-surfaced and slippery to work with these locks. I settled on a ‘truck tarp knot’ then got rud51the idea that the locking guyline adjusters off my Vaude tent might do the job – and they glow in the dark too! My Odyssee has guylines to spare.
Speaking of tension, nursing the loose prototype rudder over to Tanera wore me out much more than it should have – or maybe I just wasn’t paddle fit, having not been out since Mull. I set about making small improvements, including adding two rud64holes in the boat’s back rud63deck triangle (as Gumotex do) to make a cleaner run line for the pivot lines. It’s no great pleasure stabbing a red-hot poker into your favourite IK, but a side benefit is the rich aroma of burning Nitrilon rubber, not some cheap plastic. I’ll track down some nice eyelets later.
Once I realised the rudder board had come undone because I’d mounted the nut plate wrong, it was clear the strap looped to the last deck line sleeves weren’t doing much. rud03The main rud41mount was through the drain hole, which relied on the large nut plate (right) below to stay in place, plus the saddle strap (left) limiting any yawing. The whole plate could be slimmed down to resemble Gumotex’s factory version.
So I think I’m going to follow up on my own speculation and either form a triangular nut-plate below the deck to help keep the rudder plate in line with therudideamk2 boat or I may make a new long thin plate (yellow, left) that reaches back past the kayak’s portage strap. With a slot to get round the handle, I’ll poke another hole in the deck and this way the plate will have two mounting points plus the saddle strap and will not deflect.

rud221Rudder 1.1
While waiting for more chopping boards to turn up, I went out for another run with the Mk1.1 set-up. Much windier this time – 15 to 20mph from the SW. Normally I’d not go out in this, but the point of the rudder was to ease effort and improve control just before such conditions set in.

That was the theory – in practice I  struggled to get out of Old Dornie harbour against the wind and soon had to put in to readjust the pedal lines. What now, ffs? The luminescent Vaude clamps were effective but not a 4-second job like they should be. They can go back on the tent – better line locking mechanism needed.
If I’d looked back I’d have noticed the rudder plate had become dislodged yet again by the forces pushing the boat around. That explained why getting right out of the harbour was such a slog, let alone tackling the 15-knot headwind and lashing rain. Deceptively, there were few whitecaps out there, but a deep swell was rolling through, probably lifting the rudder out of the water. Who’d have thought it was midsummer’s day.
rud222Turning back, I hoped I might get a bit of a run on the wind, but control was even worse – shades of Ningaloo but without the mangos and barramundi. Back at the pier it was a relief to see it was only the rudder plate at fault, although I’d not have been surprised if it was just too windy for any sort of IK-ing today. While waiting for what-do-you-think-I-am-a-bloody-taxi-service? to turn up, I strolled along the exposed shore on the off-chance of finding some LDPE jetsam, but all was glistening seaweed and frayed rope.

rude2Rudder 1.2
I’m running out of time with the luxury of having the sea at my doorstep. That evening it occurred to me the rudder plate was always deflecting clockwise because the lip of one glued-on reinforcement plate underneath stopped it turning the other way. I did what I’d considered initially and glued a thin strip of LDPE to act as an opposing locating edge so the plate sat more securely once saddle-strapped down to the boat’s triangular stern.
This surely should be enough to rude11keep the plate in place, but while I was fiddling I made a template for the triangular nut plate which might further help locate the rudder plate (right). When more LDPE turns up I’ll cut one out and melt another M6 nut into it. if this doesn’t work a longer plate with another through-the-deck fixture below the portage handle (as visualised above in yellow) ought to fix this once and for all.
rude4rude6Other jobs:  trimming off the board’s unneeded flab to make the current haxagonal shape, filing down the edge of the rudder body where the lifting line rubbed (right), and one more tweaking of the rudder pedal lines.
I headed to back to the harbour where it was still blowing about 15mph from the SW but within a minute suspected it was pivoting again, possibly from the pull when dropping the rudder. The added locating strip wasn’t enough. Who knows how Gumotex manage it ruddd1but on this set-up the surefire solution is a second in-line fixing point (as above) and perhaps that triangular under-plate to stop the mount pivoting once and for all.
Partly, these issues are due to underestimating the forces that a combined 120kg of paddler in a 4.5m-long kayak moving at 4mph puts on a rudder and its mount. Add some wind, current and waves and how the small blade is fixed to a big boat becomes critical. Nearly there, brothers and one clear benefit: the ability to sit the kayak on the ground with no skeg stress. I can see me leaving the rudder on there full time and adding some sort of bombproof lock-out to make it the mythical articulated / lifting skeg.

Read about the MkII rudder.