SUP - Windsurf Modification + MUFin Wave Fin

Since getting back from a nice, long winter vacation I've been quite busy at work. A colleague is on paternity leave so I've been substituting for his two classes of 72 freshmen each, plus I have two classes of my own with 72 and 50 students, respectively. It's not too hard to teach the extra classes because they're the basic "Marine Systems" course that I've done before. It just means there's less time to work on other things, and therefore a little less time for hobbies and play. E.g., I'm still getting on the water but haven't made it to the blogging about it phase until now.

Anyway, one of my best sessions recently was one where I tried out a new Christmas present. My wonderful future in-laws got me a Maui Ultra Fins 26 cm Wave Fin; the ultimate wavesailing fin to match my freestyle-wave board, the Exocet Cross 106.



Astute blog readers might now be thinking, "I thought he already had the perfect fin for the Cross!" Indeed, a while back I proclaimed my MUFin No-Spin 32 to be the perfect fin for the Cross. I still think the 32 is perfect as a freeride / bump & jump fin for 5.5 - 6.8 sails, and it works ok in waves, too. But it's not as "loose" as a wave fin needs to be to make real tight turns and cuts on the steep part of a wave, and it's also more prone to scrape the bottom in shallow water where small waves break. I would sometimes use a 23 cm Weed-Wave fin on the Cross to get that looser feel and shallow water security. But like most weed fins, the weed-wave does everything a little worse than a regular fin of similar size. So I always felt like I wasn't experiencing the intended wavesailing performance of the Cross. Until now.

My first session with the MUFin Wave 26 was in 15-20ish mph side-onshore wind and 2-3' waves at Wiggins Pass. I used a 5.5 sail, which was at the lower end of its wind range and therefore rigged with a tight leach and loose outhaul. The fin got planing quickly and supported a good upwind angle without allowing spinout, but it definitely felt much looser than my 32 cm MUFin, and more "slippery efficient" than my weed-wave fin. There seemed to be a good balance between the edging effect of the fin and the edging effect of the board- you couldn't "ride the fin" like you would with a big freeride or race fin, but you didn't have to rely solely on the edge of the board to get upwind, either. The good blend of looseness and upwind competence helped when I needed to quickly veer upwind into a little ramp for a chop-hop. As expected, on the wave rides was where the fin felt most awesome. It let me turn the board really tight without dropping off a plane, which let me stay on the slope of the wave when turning. I'm hoping that helps me improve my wavesailing with more "surfing" style moves on the wave.

Most other sessions lately have been on the formula board or the Exocet WindSUP 11'8". I had a nice time SUPing the latter today at Wiggins Pass. The magic seaweed surf report was for 1-2' waves with 6 second period, which is pretty good for around here. I've found that any swell at least 1' high with 5 second period is rideable at Wiggins, where inlet-related sandbars perpendicular to the shoreline magnify the swells into nicely pealing peaks. Today the sandbar on the north side of the pass was working especially well. You could catch a wave near a channel marker about 200 yards out, stay on the "shoulder" of the wave all the way into the inlet, and then turn around and ride the outgoing tide back to the takeoff point. Woo hoo!

Back in "dry dock" on the patio, my modifications to the Angulo Surfa 10'4" sailable SUP are going pretty well, and I hope to be able to get it on the water by the end of this week. I routed out two rectangles in the step rocker section and filled them with high density "pour foam" before routing smaller grooves into the pour foam for the fin boxes.



I put fins in the boxes before I epoxied them in so I could be sure the boxes were at the correct angle. They came out nearly perfect, which was a huge relief. (At some point I might want to get matching fins so the board can be symmetrical, but I think if it works at all it will probably work fine with unmatched fins.)



I've since glassed the hull, but I still need to glass the rails before the final stage of sanding and painting. The rails will be the trickiest part because they have some right angles that the glass cloth isn't going to want to bend to fit. I have no idea if the modifications will work like they're supposed to or not, but I'm hoping for a board that planes early and goes fast, turns well enough for jibing and waveriding, and can catch waves easily with either paddle or sail power.