There's something about fins that makes some guys tick. Rob Pirie is one of these guys, and if you've ever wondered about what counts under your stand up paddle board, then this is the video to watch.

JP Sups have tried a new concept this year with their wave boards. They've strayed away from the industry standard of having toe and cant built into the fin boxes, and gone for a totally straight mounting system. Drawn from windsurfing origins, the straight setup makes less drag which as Pirie describes, is very important for a stand up paddle board.

Adding to his argument, Pirie straps a camera to the bottom of his board, which not only shows the sheer amount of air that travels underneath a stand up paddle board, but how the fins don't cavitate when under load during a hard turn in the waves, something which many stand up paddle surfers are looking for to stop them sliding out.

If you've ever wondered what fin manufacturers are talking about when they mention things like 'cant angle' and toe-in. It's all explained in easy to understand language by Rob. He even uses the age old beer can technique of getting a perfect right angle. You can't argue with that. 

Yes, we know it's a giant advert for JP sups and Shapers fins, but when you go to all the time and effort to make a video like this, we reckon it deserves some props.