What kind of fishing did I see

[davidpm]

I was in the Chesapeake last Sunday and saw a couple of sport fishing boats towing something that looked like a big half circle behind the boat.
It had a flag at each end and about a dozen lines running from the boat to the circle in the water.

What were they doing?
Kind of fish?
Net?

[scottyt]

sounds like they where using a planer board. it normal is uses to get the lines way out to the side of the boat