Both. That's about how wide mine are. Here's a pic of the bird sitting on the floats so you can get an idea.

The url that describes them is: http://www2.towerhobbies.com/cgi-bin...?&I=LXEKH0&P=7

Don't forget some kind of additional ventral fin at the tail for stability. If you don't have it, you'll lose control.

Finally, if you haven't put your Superstar together yet, I strongly suggest reovering the wing so you can see it. On sunny days, all that white disappears. I can't see the plane at all, and have to get my reference from the floats. I've had good results with a dark blue or black on the bottom of the wing, and nothing but Coverite Neon Red on top, which comes out a very bright orange.