The nets they use on the piers are about 3-4 feet across and have 3 ropes tied to them, which are then tied to a main rope that you use to drop the net. You drop it just below the surface and lead the fish into the net, then lift it up with the main/lead rope.

Either a pier gaff or a bridge net.


http://www.basspro.com/Offshore-Angler&153;-21/2-Hook-Bridge-Gaff/product/59546/-581146

http://www.basspro.com/Frabill-Collapsible-Pop-Net/product/10213918/-1662519

There are some cheaper alternatives if you look around.

http://www.frabill.com/landing-nets/1002.html