For echo sounder equipment, calibration is needed for optimizing results in fish finding. The echo sounder is very sensitive to water conditions , like salt levels and temperature conditions, so the results are optimal/optimized when the echo sounder is calibrated. With the New EU rules it is required to bring all sorts of fish on board, so therefore finetuning the Echo sounder equipment is a must. It has become of major importance that the ships see the right fish and catch it. This means that after the calibration job, the echo sounder results are 100 % more effective with calibrated equipment.