This article is so informative and insightful. I wanted to make sure it was seen by the mat community (even though it's not about mats). This is an article about single fins. I am a single fin believer. I have a quiver of five boards. Only one of them has more than one fin; it's a bonzer.
I, like so many others, see no reason to put more than one fin on a surfboard. I think Paul's article does a good job of explaining why that is.