Should I swap fins?

swhale's picture
swhale started the topic in Saturday, 17 Sep 2022 at 7:17am

Hi everyone, I’m a beginner/intermediate. I’m riding a 9’ soft-top board since a few months, but I’m having a hard time going down the line on bigger waves. Waves here are really fast and steep, quite small, very short and definitely chaotic (and often choppy). Always closeouts. Almost unsurfable conditions tbh, especially for a foam longboard, but still.

When waves are small (2ft or so) it’s easier for me to consistently go down the line with my other board, on which I learned for the past couple years, which is not even a surfboard. It’s a really old Windglider windsurfing board, from the 70s, huge, long, thick and very very heavy. My uncle removed the fin decades ago, so I replaced it with a plastic fin (those ones for kayaks, finbox + removable fin) which I glued with marine epoxy resin. Most times I paddle with a kayak paddle (sitting or kneeling) and when the rail engages the face of the wave that thing zips down the line fast and stable. I usually grab the outside rail to trim even more. I noticed that, although the board is thick, the rails are quite sharp. While going down the line I can then stand, walk to the nose, or lay down, sit, sometimes I even spinned on my butt 180 degrees and continued reverse. It’s fun, although you can completely forget about cutbacks and I never rode waves more than 2ft high, it's too dangerous (but I rode big unbroken swells).

That board got me more and more into surfing over the last years, until a couple of months ago I bought my first foamie: 9’ long, 95 liters, mostly because I wanted to be able to catch as many waves as possible. And that worked, I spent a lot of time in 1/2 ft waves studying the timing, the paddling, the positioning on the lineup, angling the takeoff and going down the line. I thought I got it, then bigger waves came and my sessions became really frustrating (although I also had some really good waves).

The problem is that I keep either nosediving or missing the wave. I figured that, since the waves are so fast and steep, the crucial aspect is angling the board at the right moment (too soon: you miss, too late: nosedive), which is basically also when you have to stand up. And then trimming like crazy to stay high on the face, but that feels almost impossible with the foamie: to much volume, it floats too much, it feels like it doesn’t “bite” the water at all. I saw videos of Jamie O’Brien getting barreled with a 9’ foamie, so it must be possible though.

I thought swapping fins (I have FCS boxes, thruster setup) might help, but here it gets confusing, since two aspects seem to contradict each other: in order to turn quicker at the takeoff I need agile fins, but in order to stay high on the face I would need some drive (like my old Windglider). Today (almost overhead) I decided to try and remove the central fin, and it was better, only a couple of nosedives. But I still had this feeling of a floating, indecisive board, and of having little control, little precision, which was probably worsened by the dual fin setup.

How can I improve my progression with this board? Maybe harder fins but more vertical, with less rake?


n!ck's picture
n!ck's picture
n!ck Friday, 30 Sep 2022 at 8:43pm

Hi swhale,

Another consideration… if you’re board is a true softie it might be flexing a bit which could adversely affect your trim speed down the line. If It’s one of those modern softtops with a hard eps core, that’s not relevant as they are pretty stiff like a normal ‘hard’ board.

Nose diving vs missing the wave sounds to me related more to positioning when lying on and padding the board. Too far forward equals nose dive and too far back equals missed wave. Try a few small incremental shifts of your paddling position and see if you can find the sweet spot on your board.

At 9’0” I’d personally persist with a 3 fin thruster setup for a bit more pivot but the right twin fins might work for you on your board depending on the finbox placement. Best to experiment with a few different fins and setups and see what you like best (can get expensive).

I’d hazard a guess that the fins that come with your board may flex a bit too much and not be the best quality which could affect your speed as well? Swapping them out with fins that are made for ‘hard’ surfboards would no doubt help. Don’t overthink it… take a punt on some nice fins and see how they feel.

Good luck.

Robwilliams's picture
Robwilliams's picture
Robwilliams Saturday, 1 Oct 2022 at 10:46am

Swale, I muck around a bit with idea's I have. I found the larger boards like windsurfers need to get up on a plane to become responsive but is hard to get enough speed in small waves. Think back foot and and a bit of tail area when honking. I Loosen my 8'6 by running a a 3inch modified fin raked in a rear fin box which can be trimmed by moving forward or back to find the days sweet spot of your riding style and wave type. sometimes I adjust this several times a surf as conditions change surf to surf. I run 5 to 6 inch sides to give the lift that a smaller set of front fins cannot provide. The speed of larger waves gives lift so you can reduce fins size some what. You are limited in what performance you can get out of a board by the speed you can create if that makes sense. What happens if you run a larger single fin only and move it all the way forwards. Play around with rear fin size and positioning. The board will have limits and advantages. Find the sweet spot by experimentation and understand that 9'0 if a windsurfer is going to be hard to get on the plane in small waves, Partly due to weight and sluggish drive. The faster the bigger larger boards are ridden the better they go. You will be limited by conditions and equipment. Downsize for response, upsize for paddle speed. No one size board can do every thing. What about trying a 7'6 7-0 6-10 with thickness to get you in and some more manoeuvrability in those conditions. It a compromise of paddle for manoverability. I found rear fin placement and size make massive changes to how larger boards respond under power or getting up to power and manouverability. Bigger fins create more drag especially rear. Trial and experimentation and understand the 9-0 will have limits and benefits other boards don't have. Big boards fin placement is far more critical in my experience than shortboards, in regards to performance. You can't flick an 8-0 like a 5-11 you got to drive that board and find speed. Bigger fin in the rear gives more drive but less manoverability. Compromise or downsize board can be frustrating at times but when you get your equipment dialled you will feel the balance of both response and manoverability somewhat. If the windsurfer has a pintail you will never turn it quickly under speed you could risk it by cutting 4-5 inches of rear and re glassing to experiment. Performance mal tail shapes maybe worth a look to understand how tail shape with fins effect manoverability or you can just surf it as it is and hunt down a more responsive shape for those type of waves you are surfing. Concentrate on that rear fin placement and size first and see the noticeable differences. Take three fin sizes to beach and experiment but understand the limitations of your predicament and what you are trying to do with he equipment you have. It's half the fun. On the windsurfer the tail is made to be ridden from a strapped in position, understand that the foam in this area is far far more than a typical surfboard. Therefore harder to engage under less speed or weight being applied. Tail areas are larger somewhat in relation to surfboards. Both volume and surface area. Windsurfers can also be quite flat rock-erred in tail for speed too which also can effect manoverability. You are playing with a beast of both volume and size. Sometimes frustrating and sometime exhilarating when you get it right. Experiment or downsize.