Tag Archives: packraft skeg

Sigma TXL • bow skeg and thigh straps

Sigma TXL main page
Glues and Repairs

Years ago I remember when the value of fitting packraft rear skegs was debated. Then, the now common longer sterns (introduced by Alpacka) positioned the paddler more centrally and greatly reduced excessive bow yawing.
On a packraft you’d think a skeg under the bow would eliminate the yawing endemic to short, wide rafts but turning agility would be lost. In fact, I wonder whether a packraft might yaw nearly as much at the back but you never notice. Like one of those Turkish dervishes, you’re actually pivoting from the middle of the paddle shaft, or perhaps a bit behind, at the centre of mass.

Rear skegs certainly improve tracking on IKs; you can manage without, but with a skeg you can paddle harder without constant micro-correctioning. On rivers I’ve found solo packrafts paddle fine without a rear skeg; or they’re too short to demonstrate noticeable improvements. There’s a bit of nodding as you move off which soon settles down with some momentum. Even my symmetrical Rebel 2K (left; stern identical to bow, not extended) paddled fine down the Wye without a skeg. But when getting pushed around by the swell or on sea lochs (especially when sailing) fitting a skeg was worthwhile.
Either way, rear skegs are a thing now with packrafts even if you don’t have to fit them every time. Certainly on my longer TXL I like to think the stock rear skeg aids coastal paddles; though we found a brief stint with no skeg was only slightly noticeable, paddling into the wind in a sheltered loch (no swell). Anyway, I’ve been curious to see what effect a frontal skeg has, so on buying my TXL I ordered a spare skeg and patch which Anfibio also sell separately for €21 + €6.

Goop no good; Aquasure OK; Helaplast better

Gluing on a skeg patch
As stick-ons go, this is not a mission critical job but you want to line it up dead straight which I now see is better done with the boat inflated. I just used the rear seam, hoping it was along the middle line. Anfibio recommend Helaplast which they can’t post outside of Germany but which you can buy on ebay.uk (from Germany…) for €7 for 50ml.
There must be something similar in the UK, but the problem is identifying it against something that provenly works. I had some Goop contact adhesive, but whatever the ‘Automotive’ variant is, it did not stick at all. So I decided to try some Aquasure+FD, leaving it to cure for half an hour before sending in the roller. That seems to have worked.

Using stock TXL mounts sort of works

Thigh straps
Part of me likes to think I’ll be using my nippy TXL the way I use my IK: fair weather open-water transits rarely more than a mile from shore. As this might require sustained periods of paddling I figured some thigh straps would help, as they do in my IK. It’s not so much for hardcore bracing or even rolling, the way they’re used in white water, but just to lock-out the legs so the core is more responsive and you can get good drive, as with knees pressed up under the deck of a hardshell sea kayak.

Anfibio sent me their latest 5-point thigh straps which I tried and liked on the Revo (left). But to make full use of them would require gluing on up to 8 extra patches (if not ideally the ladder patch; left).

I decided my old Anfibio 3P straps which I’ve used for years in my IK would be OK for my low-tension, flatwater use, and require adding just one pair of loop straps. I could have got away with the unused flat patch by the seat, but the direction on tension was off centre and would eventually wear, stretch and maybe break. These small patches are not really designed for such loads and now my Helaplast has arrived I decided to try it. An old post on the Anfibio blog explains how to use Helaplast:

  • mark off area on hull
  • mix hardener 20:1
  • clean surfaces with solvent
  • apply a thin layer to both surfaces and wait 30 minutes
  • apply another thin layer and wait another 10 minutes
  • Position patch; it won’t adhere properly
  • Heat with hair dryer to reactivate glue and press down hard (it’s better if the boat is deflated to do this on a hard surface).

The heat reactivation trick was not one I’ve heard of before with glues (except to loosen stuff), but you could see it worked. Where the positioned patch was lamely stuck to the boat, a bit of heat saw it bond down well with some some added rolling. You can tell when something looks well glued and this feels like it, though I’m sure glad I didn’t have to do that another six times.

Update
Having paddled about with the straps a bit, they work OK, but the front mounts need to be lower to hook well over the knees without using the cross-link strap to pull each strap inward (not what they were intended for). I did this a few days later.

Thigh strap attachment points are better off set low at the front.

Inflatable kayaks: Do you Need a Skeg (Tracking Fin)?

Updated Summer 2022

See also:
About rudders
About decks

Skeg-wheel trolley!

Short answer: Yes.

Generic, over-tall Chinese-made skeg.
Snap-prone but easy to trim.

A skeg is like a fixed ‘rudder’ under the back of the boat and makes it easier to go straight (track). Only the very cheapest single-skin vinyl IKs don’t have skegs (Grabner, one of the most expensive IKs, is an exception; though it’s an option). If you’re IK doesn’t have one, it’s easy to glue one on (see below).

grabgumskeg

Some flat-floored IKS have up to three (imo, a gimmick) and many skegs on Chinese-made IKs are unnecessarily tall (too deep) which makes them snap-prone. Just about all skegs can be easily removed by hand, because in shallow rivers you might want to do so to avoid grounding. You can as easily buy a spare and trim it with a hacksaw.

Original over-sized Gumotex alloy skeg on the left. Later smaller; now tough plastic.

Years ago Gumotex introduced a slip-on, black plastic tracking fin (skeg, above) which was near identical in shape to one I’d had made to replace the old-style oversized alloy skeg (left). A smaller skeg made better clearance and still tracked fine. But metal bends; tough plastic is much better and that’s what all their boats come with now.
I’ve fitted these plastic skegs to older Gumotex IKs and other IKs. The kit is about £25 + glue, and the plastic skeg is pretty much unbreakable. Just make sure you glue the mounting patch on really well; it helps if your boat is made from a matching rubber fabric as the supplied Nitrilon patch or make your own patch from same fabric. But I have glued PVC to rubber successfully – use good two-part glue. The pictures below help you see where to position a skeg.

I fitted the Gumotex plastic skeg to my Grabner Amigo IK (above) and at sea used it all the time. But on the shallow River Spey (below) this boat didn’t handle at all well without a skeg, possibly because the tailwind pushed the kicked-up stern around. It was really quite annoying because a few years earlier my broadly similar Sunny managed the Spey just fine without a skeg, so skeg-free tracking clearly varies from boat to boat.

spey1304

Paddling without a skeg
If you’re an experienced paddler you’ll have acquired the knack of going straight without a skeg – handy for paddling shallow rivers where the skeg would ground. A little more paddling finesse and constant small corrections are required, especially if powering on.
It’s good to learn this technique before you need to: fix your eyes on a tree or marker on a distant bank and paddle as gently as you like towards it, not looking away and keeping the nose of the boat in line with the marker. By using very light strokes you’ll see it can be done if it’s not too windy when again, a skeg helps with tracking (going straight).

cezesolar
Gumo Solar with no skeg

I even found I could paddle a ten-foot Solar 300 (above) without a skeg. Once you know you can go straight without a skeg, it’s just a matter of adopting the same finesse but with a bit more power. Only when you attempt the speeds of a Viking longship will bow deflection or yawing get too much because to paddle faster and still go straight you need a skeg. Out at sea or on busier rivers, I always use a skeg.

I’ve often thought a hinged retractable skeg would be a good idea: it would pivot backwards when dragging in shallows, then drop back down when there’s enough depth. It seems SUPs need skegs and in the US, FrogFish have made such a thing for boards, but you hear the spring can be a weak point.
If your kayak has a rudder mount (or you can make one), another way of doing it is fitting a swing-down skeg similar to kayak rudders. It works the same way as a rudder with a looped cord swinging the skeg up over the stern, or down into the water. The pivot skeg shown top right is made by Advanced Elements for their AirFusion IK and costs about $/£80. Or have a look here.

Packrafts

On shorter, wider, slower solo packrafts the consensus used to be that skegs made little difference. Especially when unloaded and with a full-weight paddler, the bow yaws merrily left to right as your paddling pivots the boat from the back. Or so I used to think until I tried the skeg on my Rebel 2K. Up to then I’d been ambivalent about them – using the same boat fully loaded a few weeks earlier on a fast flowing river, yawing had not been an issue. But unloaded (and with my generous 95kg of ballast) yawing was notably reduced with a skeg. Speed however, was the same or was too small to measure.

Longer stern puts you more in the middle of the boat.

One reason some packrafts may manage without a skeg is that way back in 2011 Alpacka invented the ingenious extended stern (right). It helped limit yawing much like a skeg, and effectively positioned the paddler more centrally, like a kayak, while also adding trim.
This idea has been widely copied by just about everyone since and it definitely works, compared to the original Alpackas. But as mentioned, once there’s a good load over the bow, yawing is reduced in any packraft. Anfibio sell a detachable shallow skeg and glue-on patch for €21. My Rebel 2K came with a skeg and I must admit I use it most of the time now. But it does not have a fully extended stern like the Alpacka above right. Then again, my longer Nomad tracked great without the skeg.

Frontal skeg?
Now I have a longer 2.8-m Anfibio Sigma TXL and I am curious to see if adding a frontal skeg will take a difference. Seated centrally or two-up, this boat does not yaw from the boat like an unloaded solo packraft, but it does wander a bit (track poorly), especially with the inflated floor pad). Results soon.