Okay, if you're going to choose a twin with a trailer, basically what it is it's your base is your twin fin setup. Basically you have your big side fins, that are bigger than your tri-fins. And then sometimes on a twin fin, you kind of get a little slide into the turn, for on those bigger days you need something more to hold the tail down and give you more of a positive traction in your turn. So basically, what they've done, is you still have your side fins as they're holding into the face of the wave, and then you have a small trailer fin in the back that is just holding down the tail just a little bit so that you get that positive feel as a thruster, but still you get the speed of the twin fin.
So the water flow is coming down the bottom of the board, wrapping around the bigger side fins, holding it in to the face of the wave. The flat side is giving it lift, and as it wraps around the small trailer fin and then releasing. No, basically your small trailer fin, it's not taking a lot of speed away from the board. So that way, keeping it small, you still keep that speed of the twin fin.
These boards are real fun, they go rail to rail real easy, they're a fast board and they're a great summer board for the summer time. And that is your twin fin with trailer.