As we where racing in Kemnade,
www.sup-mag.de/races_events/ergebnisse/np-german-sup-trophy-kemnade--bericht-und-ergebnisse

a lake in the german Ruhr-area, all competitors had to fight weed.
Hardboardriders used seaweedfins,
www.seabreeze.com.au/forums/Stand-Up-Paddle/SUP/Help-wanted/
but there was no option for inflatables with slide-in fin boxes.





So we developed a fin we called "Die Wand".
http://supball.de/index.php/isupi/whois




there will soon be an english page available,
Bernd@supball.de

Sorry to change subject, but I notice in your profile pic that appear that you are paddling indoors with a water polo ball alongside.

Do you play some sort of SUP Polo?

As someone who is a regular water polo player and also enjoys SUP, I'd love to be able to give that ago sometime.

as we are playing supPolo in germany, this
www.seabreeze.com.au/forums/Stand-Up-Paddle/SUP/Supball/
should be nearer to you.