Whenever we get the same question several times, I figure we should attempt to preemptively answer it.
This question relates to the Pleasant Pheasant, and more specifically, the decision to add side-bites.
Round tails traditionally don't have tremendous "drive" meaning, they lack the surface-area and lift to generate speed. (Compared to a square tail or swallow tail) But what they lack in drive, they make up for in a nice, tight turning radius.
We wanted to make the Pleasant Pheasant a round tail, to allow it to make tighter turns than say, the Joy. But we also wanted to give it a bit more zip, so we added the side bites, to give the tail a bit more drive and control.
When you go to pump the board, you are side-loading the fins with pressure that gets converted into forward acceleration.
The small side-bites also assist in keeping those tight, pocket turns under control and efficient.
You can read more about the Pleasant Pheasant model here.
And you can view/purchase a set of the 3 1/8" Side-Bite fins here.