Underwater currents can distort the shape of the net, causing it to collapse, drift away from the target zone, or tangle. Aligning a net against a shifting tide requires immense calculation and physical effort.When fishermen are actively setting and aligning drift nets (which float vertically in the water column without being anchored), the process is highly dynamic and dangerous. Because drift nets can be miles long, a lot can go wrong during the actual deployment and alignment phase: