Do some of you ever switch back to single fin?

(after a decade or plus not bothering, I switched back a modern tri to single in a FFS moment and was rather pleasantly surprised of feel and performance)

I experimented with tris for a short time and stuck with singles. But my attempts with tris may have been less than optimal.
There's always the danger of going with trends, or what is fashionable, isn't always the best option.

I use thrusters on my surfboards. But found on a windsurfer, if fins were parallel that reduced manoeuvrability, if toed in, one fin would tend to cavitate/ventilate. Single was much easier for this bear of little brain.
And I've never had any complaints about how my singles perform. They can get vertical up and down on medium sized waves, and jump well.

The debates used to rage over what was the best fin set up in a wave board, and in the bad old days a lot of new multi fin boards weren't great simply because the fins supplied and box positions didn't always work with the board shape. (And those hull shapes were themselves changing a lot, at the time. )
Hopefully those days are now gone and there's little need to fiddle with a new waveboard, in terms of fin tuning.

What this leaves us with is the simple differences between these alternative fin set ups, and none of it really relates to what people do in surfing because our rigs apply different sideways pressures on our windsurf boards.

In windsurfing a single fin remains the fastest set up, due to minimising drag, but is the worst for turning, and that's because a long single fin gives a 'torque' force which levers the board tail out of the water at speed. That leverage helps the board to 'fly' off its tail section - like with a slalom board - but sometimes also makes the board 'tail walk' uncontrollably at speed. So the single fin is not great for board control, in windy conditions.
Speed on a wave board is useful for jumping, but most wave sailors are more concerned about turning the board on a wave face and shorter multi fins allow that better, because they don't lift the board tail much, and you can concentrate on carving the rail more. The board can also turn in a smaller circle, especially if you reduce the total fin area.

So:
A single fin works better for bigger size sails, and for speed, and for optimising early planing.
A twin fin set up is the loosest, because two relatively small fins sit side by side, meaning you get little lift from the fins at slow speeds, so you get the benefits of a slidey tail.
The tri fin set up is an obvious compromise, because you can keep the centre fin, if a shorter one, whilst also having the benefits of thruster fins on the rails.
The quad fin set up feels very planted in the water, but allows a lot of drive and backfoot pressure for those cranked tail turns.

With these basics in place, it's then down to rider preferences, and what works with your local conditions.

Do a 2023 trifin work as a single fin? Asking for a friend...

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flyingmujol said..
Do a 2023 trifin work as a single fin? Asking for a friend...

Yes.
You'd just fit a slightly longer centre fin and then remove the thrusters fins. But you also need blanking plates for the thruster boxes, so as not to increase drag.

The other possible issue depends on the centre fin box fitted to the board - because ideally you'd want to shift the new single fin forwards a bit, to compensate for the lack of thruster fin area.
With a US box fitted you'd have more positioning range, and you just experiment with where the new fin is best positioned.

If no fore-and-aft adjustment is possible for the centre fin then your only other option is to use a replacement fin with less rake or which is less swept back at the tip.
For blasting that might not matter, but for turning it might alter the handling characteristics of the board a lot.


As it happens, I went back on a single fin board today, as the wind was a bit marginal and the sea was flat. The modest 22cms fin used in a 100 litre board was still long enough to collect bits of our local seaweed - an issue which doesn't usually affect multi fin wave boards.

Multi fin for strong winds or decent waves. Cabarete hasn't much of either so mostly small single for me. Sometimes I go quad to mess around. Puffy winds and sideon wind shadow is dreadful for multi fins.

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Doggerland said..
Do some of you ever switch back to single fin?

(after a decade or plus not bothering, I switched back a modern tri to single in a FFS moment and was rather pleasantly surprised of feel and performance)

You just need to watch this to know multi fins are overrated.

I am not convinced any more that multi fin is an advantage at least not a big one. Depends also on your style and what you expect or want.
I myself started using single fin again and I like the much better drive in the bottom turn. The top turn is not so slashy but that is not what I am looking for anyway.

Hehe, TT would probably perform some stunning rides without fins at all, but yeah :)
Anyways, for me it was a bit of a revelation how well a newer 106l (under 98kg) performed by just taking off the thrusters.
As a relatively heavy sailor, i hardly considered it and expected all kinds of agility losses because back in the days, multi-fins provided a clean break from the woes of larger volume single fins. With modern hi-volume wave shapes, this doesn't seem to hold up.
Over here not many try it and it is definitely worth a try!