A Double Rig Shrimp Trawl Illustration. Royalty-Free Stock Image

A double rig shrimp trawl is a fishing technique that involves towing two trawl nets simultaneously from a single boat. Trawl nets are shaped like a cone or funnel, with a wide opening to catch shrimp and a narrow, closed cod-end to retain the catch. Trawl nets are towed through the water column or along the sea floor. The speed at which the net is pulled is important, as too fast can cause a pressure wave that pushes the shrimp away, and too slow can cause the net to dig into the bottom. The booms used in double rig trawling are shorter and lighter than other trawls, and are rigged so that they can lie horizontally in cradles along the rails when not in use.