Category Archives: Packrafting Guidebook

Sigma TXL: floor-mounted skeg and foam backrest

Sigma TXL Index Page

After various trials I decided for sailing the TXL would benefit with a skeg on the floor where it would be fully submerged except momentarily when cresting bigger waves. The standard position angled on the stern (left) sits too high on the buoyant TXL so doesn’t have much effect, though the TXL tracks pretty well on flat water, with or without the air floor, solo or two up. You can mount the skeg back-to-front (right) for more bite, but I hope tracking when sailing will be greatly improved with a fully immersed skeg. When the wind allows, I want the TXL to be a reliable sailer on longer paddles.

Under the floor stays fully submerged, even with the air floor.

I could’ve simply made an extension to the stock skeg, but decided having two positions for the stock skeg would be less bulky. Like on an IK or a SUP board, the long but shallow Anfibio skeg would work well mounted horizontally under the floor (above, left). I’d already tried a skeg under the bow, but that did not work well at all. Waiting for good glue, I’d stuck that front skeg patch on with Aquasure and was surprised how easily it peeled off with less than a minute with the hairdryer.

Just as I was about to clean the removed patch and glue it on with Helaplast (recommended by Anfibio), I thought super tacky Gorilla Patch & Seal tape would be even easier, using the spare Anfibio skeg patch as a template. But I decided P&S is just thick ‘rubber’ tape suited to sealing, not supporting a knocked about skeg. In fact regular, string backed Gorilla ‘duct’ tape would have worked (a good way to test the idea), and I’ve found lasts surprisingly well on a packboat. In the end I decided the liberated fabric-backed Anfibio patch would be best.

The most important thing is to mount the patch straight along the centre line otherwise you’ll be going round in circles. This is best judged with the boat inflated. After that, it’s the same Helaplast sequence as detailed here. While gluing, I decided to add a couple of tabs low in the front to make the thigh straps hook more effectively over the knees.

The benefit of having two positions for the rear skeg instead of a bigger fin is that you can choose: use the standard position for shallow rivers (if a skeg is even needed) and use the floor mount on open water where wind and waves may push the boat around more, and if you hope to sail in a straight line.


Foam backrest
Sat up front, the stock inflatable backrest (below left) does the job, but in a low-pressure boat, the air cushion just adds more mushiness where you want support. As I say in the book or on Seats: sit on air; lean on foam. There is no advantage to inflated backrests other than saving a bit of packed space (might they also be cheaper to produce?). In this way, regular solo packrafts, where you lean on the back of the boat are better. Seated centrally in the TXL, you need a supportive IK-style backrest.

After a few outings I’ve decided to replace it with a spare foam SoT backrest (below), an idea which has worked well on my IKs for years. IK makers too have a blind spot when it comes to front seats. Today’s price for the backrest on ebayUK is 17 quid (left). Once I ditched the heavy ‘brass’ clips which came with mine, it weighs 200g, only 40g more than the Anfibio item (the ebay one shown left uses lighter plastic spring clips).

The foam backrest fits right on the TXL: the long tapes reuse the TXL’s front buckles and, less well, the rear straps come back through the flat tab mounts. A slide ring would work better here. I could have reused the thin, cinchable elastic cord which came with the Anfibio backrest but I suspect it was part of the problem (and thought so on the Anfibio Revo too). Counter-tensioned, non-elastic straps attached to a firm panel add up to better support. Up to a point the thinner foam backrest also makes more room behind it, too. And I won’t miss deflating the stock backrest to save on packed space, neither!