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Blackfish Paddles x Kirsten Marina Lefeldt: Introducing the new Blackfish WS241 fin built for weed-free speed

April 15, 2025

By Anna Nadolna

Blackfish Paddles has just unveiled the WS241 (Weed Speed) fin designed for speed, tracking and glide without getting caught up by weeds. 

Blackfish Paddles has just unveiled the WS241 (Weed Speed) fin designed for speed, tracking and glide without getting caught up by weeds. This is the latest addition to Blackfish high-performance fin range developed in collaboration with the world class SUP athletes including Amandine Chazot and Sam McCullough. 

The idea behind the WS241 fin was sparked by significant input from Chicago-based racer and coach Kirsten Marina Lefeldt, kicking off the design and prototyping process. 

Built on real-world feedback and tested in the unique SUP conditions of Lefeldt’s home base in Chicago, this fin is tailored to meet the demands of paddlers navigating complex aquatic environments - from thick Pacific kelp to tangled grasses of freshwater lakes and rivers. 

The Weed Speed is a great all-around fin for any paddler looking to maximize performance and forget about getting bogged down by weeds once and for all. The longer base of the WS241 “Weed Speed” delivers excellent tracking, while the cutout on the trailing edge keeps things agile for smooth buoy turns. 

Kirsten Marina Lefeldt shares the behind-the-scenes story of the WS241 fin: 

Nothing beats the rider-owned and tested approach! Could you tell us more about your collaboration and the development process of the Blackfish WS241 Fin? 

It was after the Belle Isle Race in Detroit, which will be the race course for this year's USA SUP National Championships, a race course where you encounter weed a lot. 

I was chatting with Matt Lennert at the after party and we both agreed that it would be great to bring back the weed shedding fin design that he had developed for BlkBox back in the days. An idea was born and I shortly after made the connection between Matt and Blackfish Paddles. A prototype was developed based on the BlkBox design but with the lighter and more advanced material we are used to seeing in the Blackfish fin product line. 

Beyond weed resistance, what other performance benefits did you discover during the testing phase of the Weed Speed fin?

I tested the fin in Chicago against other fins and was amazed by its tracking abilities and speed. 

Who would benefit most from using the Weed Speed fin, and what types of paddling conditions is it best suited for?

After testing this fin in both flatwater and in choppy conditions, it definitely shines in both of these conditions. 

Here in the Midwest we often deal with lots of weeds in our lakes and rivers. Getting weed stuck on your fin can cost you your race. It happened to me at the Belle Isle race in Detroit. Having a weed shedding fin that compares to other fins in stability, tracking, and speed, will be a huge advantage. 

Learn more about the WS241 fin

The WS241 fin is available to order now at your local Blackfish Paddles dealer