Truefin first conducted subjective human flutter kicking tests in swim pools with very good results, however it was not possible to reliably and repeatably quantify thrust comparisons between different fin manufacturers. Truefin then built a test tank apparatus and equipped it with a motor driven artificial flutter kicking leg and measured the horsepower (corresponding to muscle exertion) with a rotary torque sensor measured at the output shaft of the motor, and measured the kicking thrust (pounds) with a load cell at the artificial 'hip joint' as a controller automatically kicked the fins from 1 to 100 kicks per minute while collecting data with SENSIT FUTEK software. Two different kicking range of motions were tested (27 inch and 36 inch 'swept tip') during all tests. Machine test results regarding thrust and efficiency of Truefin versus various categories of other fins are represented graphically at www.truefintechnical.com at COMPARISONS (PDF). Upon observation of the data it is apparent that Truefin provided up to twice the thrust (100% greater thrust) at specific kicking frequencies, and also Truefin had up to 65% better efficiency, depending on the brand tested. Relatively flexible fins of low quality were outside the scope of Truefin testing. Truefin has the comfort and easy kicking of highly flexible fins because Truefin readily forms an angle of attack which is enforced by rigid articulating spines, yet Truefin has measurably higher thrust then the stiffest technical fins. This results in an easy and highly efficient kicking experience when Truefin is kicked slowly, while also being a powerful fin when kicking rapidly. All tests were conducted, and all reports prepared, by an independent engineering consulting company.