Weed fins: "Some boards were not designed with seagrass in mind" - Basti Wiepcke in an interview
Manuel Vogel
· 29.08.2025
Basti, on Fehmarn, as on many other spots, nothing works without weed fins. How many seaweed fins do you sell each year?
I would say it should be around 300 to 400 pieces. We have a few brands in the shop: Maui Ultra Fins, K4 Fins and Concept X.
Is the question of the right size asked most frequently?
Yes, but the consultation is often about seagrass, but also about fins for shallow areas. Ideally, customers have their standard fin with them and we can put them on a grass fin. The grass fin can then be selected so that it has approximately the same surface area as the standard fin. However, the grass fin should not have less surface area. If the grass fins become even smaller, there is hardly any counter-pressure and you have to ride very sensitively to avoid spin-outs and still be able to run upwind.
If it is not about seaweed, but only about water depth, for example in the Dutch standing areas, would you recommend using a shorter standard fin or a seaweed model?
If your board has a standard 40 mm fin, but you have to make do with a draft of 30 centimetres due to the depth of the water, I would always recommend a weed fin. A 30 cm weed fin has about as much surface area as the 40 cm standard fin; this way you can still put comparable pressure on the tail without getting spin-outs. Planing is also about as good. Of course, the board runs a little flatter, pulls less height and turns less tightly, but you inevitably have to live with that. A standard 30 mm fin would simply be too small in terms of surface area.
If the water is not deep enough, I would always recommend a weed fin!"
Some brands move the weed fins forward on the base so that the centre of effort of the fin remains further forward. What is the feedback from your customers on this?
This concept is actually positive. You should just make sure that the nose that protrudes from the front of the box is flush with the underwater hull of the board. Some boards already have a bend in this area and then there is a small gap in which the seaweed gets caught. If necessary, you can glue on a suitable piece of foam with superglue, for example from the fin cover.
Are there things that cause problems with weed fins?
On some Starboard models or the new Goya One, the standard fins on the base are already offset further forwards. The application with weed fins has therefore not been considered here. From the 2026 season, the fin boxes on Duotone waveboards will be so short that the fin base will just fit in without the possibility of moving it. This is intended to save weight, which of course means that weed fins cannot be mounted further forward. That's a pity. Goya has already responded to this criticism and made the boxes a little longer again.
I have a tip for large freeride and freerace boards, which are often "foil ready" and therefore come with a tuttlebox: If it's a deep tuttle box, you can also use normal tuttle box weed fins, but you should use an adapter. In other words, because the box is deeper than the fin base, there is a gap in the fin box. This is filled with the adapter. This prevents damage to the box and fin if you should ever run aground in shallow water.
